First recorded in the 8th century ad, the earliest grenades were Byzantine incendiary weapons, employing the mysterious “Greek Fire,” akin to modern napalm. In the ensuing centuries the technology spread through the Islamic world and into the Far East, with the Chinese refining the weapon to feature a metal casing and a gunpowder filling. By the 16th century the weapon had entered military service throughout Europe, and grenades were cast-iron spheres 4in or larger in diameter with a time fuse fitted – reminiscent of those carried by cartoon spies. Instead of waxed candle wicks, the fuse was now a flaxen cord rolled in dampened gunpowder and dried. Grenades weighed to 2.5lb and sometimes more. This was to be the standard design for the next 300 years. According to Peter Whitehorne, one observer of the European military scene in the 1570s: “These balles, after they are fired and well kindeled, and having blowen a little must be quickly throwen, lest they hurte such as hurtle them” (quoted in Heinl 2013: 136).
By the late 17th century most European armies included assault units of infantrymen specially trained to throw grenades. Dated 1744, these watercolours by Andrew Lens (c.1713–after 1779) depict stages of a British grenadier’s drill movements. Grenadiers were selected from among the largest, strongest, and bravest soldiers to lead assaults and hurl grenades at the enemy’s positions in advance of the main body. The attacking grenadiers carried lit “slow matches” – slowly burning fuses from which to light grenade fuses. (Anne S.K. Brown Military Collection, Brown University Library)
An example of the types of grenades used from the 1600s all the way to World War I – a cast-iron sphere filled with gunpowder and fitted with a thread-wrapped cotton wick rolled in dampened gunpowder or sulfur and dried. The term “grenade” is variously said to be derived from the Latin word for pomegranate, pomum granatum (meaning “apple” and “seeded”), or the Spanish word for the same fruit, granada, owing to the size and shape of early spherical grenades. “Pomegranate” in French is grenade while a pomegranate bush is a grenadier, which is also the French term for a grenade-thrower. To differentiate a pomegranate from a French hand grenade, grenade à main is used for the latter. The word “grenade” is also said to be derived from the Latin term for grain (as in corn), granum – a less likely name source. This may have referred to the coarse-grain gunpowder used as explosive filler in early grenades, which was described as “corn grains.” The English originally referred to the grenade as a “grenado” at least into the 1700s. During World War I, though, the British simply referred to their grenades as “bombs.” This originated from The Grenadier Guards protesting that grenade-throwers throughout the Army were being called “grenadiers,” an infringement of the regiment’s privileges. In 1916, King George V subsequently ordered they be called “bombers” or “bomb throwers.” Today, many European countries use a term derived from granat with variants in spelling. Italy uses bomba (pl. bombe), but colloquially uses granata (pl. granate). Note that “grenade” can also refer to HE projectiles or cannon shells in some languages, for example the German Granat-Geschoß (HE shell) or Granatwerfer (grenade projector – a mortar firing HE rounds). (Author)
In the 1700s, the British used 3lb and 6lb grenades filled with 3oz and 5oz of gunpowder, respectively. Explosive grenades were also used aboard ships for boarding and repelling boarders. Lighter and less costly than cast-iron grenades, thick tempered-glass spherical grenades appeared in England in 1685 and were used up to the 1850s to enhance fragmentation effects. Cast-iron grenades often broke up into only a few large pieces, resulting in insufficient casualties. The explosive flash of a gunpowder detonation also caused casualties – burns and internal concussion injuries, especially within trenches and enclosed fortifications.
Although the term “grenadier” continued in widespread usage – normally denoting elite troops – by the time of the Napoleonic Wars (1796–1815) such soldiers generally eschewed the weapon that had prompted their designation. Grenades were essentially siege weapons, being used mainly by defending troops, who threw them into approaching sapper trenches and the ditches surrounding besieged fortresses. Attackers sometimes employed them, however; in 1836 the Mexican Army employed grenades at the Alamo, and grenades were used by all sides during the Crimean War (1853–56) and the American Civil War (1861–65). Following the British use of grenades in the Sudan during 1884–85, homemade grenades were used by besieged British forces during the Second Anglo-Boer War (1899–1902). A British artillery manual of the 1880s offers a brief comment of the intended purpose and nature of such weapons: “[Grenades] are used chiefly for the defence of places against assault, being thrown among the storming parties in the ditch. They are useful in the defence of houses. They can be thrown by hand about 20 or 30 yards. They are of two sizes, 6-pr and 3-pr” (Anon 1887: 78).
As with so many aspects of warfare, it was the Russo-Japanese War (1904–05) that provided the world with clear indications of the potential of the grenade as a mass infantry weapon. During the Japanese siege of Russian-held Port Arthur, grenades were extensively used by both sides. The Russian defenders were the first to employ them, using old cannon balls – or brass artillery cartridges cut into 4in lengths – filled with dynamite; to prevent premature detonations a mining safety fuse was attached, as it did not spark as much as the earlier type. The Japanese besiegers used meat tins, pottery jars, and bamboo sections filled with a pound of pyroxylin or picric acid (two early military explosives). Attacking Japanese grenadiers even carried burning slow matches to light grenades like the earliest grenadiers. The Japanese appear to have been the first to add handles to grenades to increase their throwing range; they also used fabric stabilizing streamers to improve grenade accuracy. The Russians provided standardized instructions for fabricating grenades, and the Japanese mass-produced grenades on-site using cast-iron pipe. Besides defensive use, both sides employed grenades to “open gaps” in crowded enemy trenches, allowing friendly assault troops to use their bayonets. Grenades were also used to clear rooms during village fighting, portending one of the weapon’s principal uses during World War II.
The American Civil War saw a reemergence of grenades, mainly for defensive use. These were of more advanced design than the previous iron ball with a fuse, as they now had mechanical fuses. The Ketchum grenade – pictured here lacking its stabilizing wooden tailpiece with fins – Hanes “Excelsior” grenade and Adams grenade were quite innovative, but were complex, costly, and dangerous to users owing to their sensitivity. Confederate soldiers mixed gunpowder and musket balls in fused glass bottles and Union soldiers used 6lb cannon balls as grenades. (CC BY-SA 3.0/Minnesota Historical Society)
The Italo-Turkish War (1911–12) saw the use of grenades in the first documented instance of explosive devices being dropped from an aircraft. An Italian flyer, Sotto-tenente Giulio Gavotti, armed four cipolla (“onion”) grenades, lit them, and dropped them on Ottoman positions in Libya on November 1, 1911. The bombs were orange-sized, 4lb iron spheres filled with potassium picrate and fitted with a safety fuse – akin to the grenades of the 1700s. They inflicted no casualties. What can be considered the first modern percussion grenade, however, had been developed in 1903 by Miloš M. Vasić, an officer of the Serbian Army. After further refinements, his design saw service as the M.12 or “Vasićka” during the First and Second Balkan wars (1912–13).
The grenade body contains the filler (explosive, chemical, or pyrotechnic). It can be various shapes: an oval (egg or lemon), a sphere (ball), a cylinder (can), or a truncated cone (a cone with the apex cut off). A sub-class of grenades is the stick grenade or “potato-masher,” fitted with a throwing handle. The body also serves to attach the fuse, arming, and safety systems. A fuse well is usually in the grenade’s top and a filling or charging hole in the bottom, side, or near the top. The fuse well and filling hole may be the same. Most grenade bodies are made of cast iron or thin, one- or two-piece pressed sheet steel or tinplate. The seams of rolled metal body grenades are crimped and/or soldered. Other materials include aluminum, tinplate, brass, Bakelite (plastic-like synthetic resin), plastic, glass, compressed fiber, treated paper, cardboard, ceramic, and even concrete and wood. The last three were in extremis substitutes because of the lack of more viable materials. The segmentations cast in the body do little to create fragmentation and are provided to ensure a firm grip with wet or muddy hands. Modern plastic-bodied grenades have external ridges for the same purpose. Very seldom are internal segmentations used, but this does aid in fragmentation.
A Serbian M.12 grenade. It was one of these that was thrown by Nedeljko Čabrinović, a young Bosnian Serb nationalist, at the car containing Habsburg Archduke Franz Ferdinand in Sarajevo on June 28, 1914; the 10-second delay meant it missed its target, but wounded 20 bystanders. The archduke was killed later in the day to start the sequence of events that sparked World War I, a conflict in which grenades would become essential defensive and offensive weapons. (© IWM MUN 3261)
To the left are the larger fragments including the base from a British No. 36M Mills Bomb. To the right are fragments from a US M67 grenade. These are only a fraction of the fragments generated from both types of grenades, most of which were much smaller. A Canadian 10-cent coin (0.71in in diameter – slightly larger than the US 10-cent coin) is included for scale. The author has found US Mk 2 “pineapple” grenade fragments on grenade ranges with 2–6 segmented sections still in a single piece. Some antipersonnel blast grenades were provided with steel fragmentation sleeves that slipped onto the body, converting them from blast to fragmentation. Enhanced fragmentation means is incorporated in many post-World War II grenades – internal fragmentation liners in thinner bodies or coiled steel wire scored at intervals. Smooth cast- or sheet-metal bodies do provide some degree of fragmentation, but the few fragments are too large, irregular in size, or too small and light to be lethal. (Courtesy of Darryl W. Lynn, the Grenade Recognition Manual-series)
A grenade’s filler defines its purpose(s). Fillers include high explosives (HE), chemical (smoke, incendiary, irritant gas), and pyrotechnic (flares, smoke). HE fillers are intended to shatter grenades to produce fragmentation and blast effect. The shattering effect is called brisance. The relative effectiveness of common grenade explosives is compared to TNT (trinitrotoluene), which has a value of 1.00.
On its own, ammonium nitrate is comparatively low-powered. To make it more effective it was mixed with additives. Alumatol consisted of 77 percent ammonium nitrate, 20 percent TNT, and 3 percent powdered aluminum. Another was British Burrowite, with 74 percent ammonium nitrate, 16 percent TNT, and 10 percent powdered aluminum. French Schneiderite was composed of 88 percent ammonium nitrate and 12 percent dinitronaphthalene. Ammonium nitrate-based explosives disappeared after World War II because of the development of more advanced explosives. Owing to shortages of materials during World War II, black powder saw limited use as a substitute filler by the Germans, as well as being employed as a starter compound. It is made from 75 percent potassium nitrate (“saltpeter”), 15 percent sulfur, and 10 percent charcoal. It is highly susceptible to moisture, but once dried, will ignite. Picric acid was one of the earliest military HE types and was used by France, Germany, and Japan from the 1880s. It reacts with metals when moist to form sensitive compounds. This required the inside of grenades to be varnished. It is more easily detonated than TNT, but resists shock to about the same degree.
TNT is one of the most widely used explosives, coming into use after 1900. It is a component of many other explosives (amatol, pentolite, tetrytol, baratol, Torpex, tritonal, picratol, ednatol, Comp B). Stable and insensitive to blows, TNT requires an explosive shock to detonate it. Amatol is a mixture of ammonium nitrate and TNT. The first number always indicates the percentage of ammonium nitrate and the second, TNT. Amatol is insensitive to friction, but may be detonated by severe shock, being less sensitive than TNT. Amatol 80/20 is slightly less powerful than TNT and produces white smoke. Amatol 50/50 explodes with slightly higher force than TNT. Comp B appeared late in World War II and is still widely used in grenades. A combination of 59 percent RDX, 40 percent TNT, and 1 percent beeswax, it is very stable and one of the more powerful explosives.
| ammonium nitrate | 0.42 |
| black powder | 0.55 |
| picric acid | 1.00 |
| TNT | 1.00 |
| amatol 50/50 | 1.20 |
| tetrytol 75/25 | 1.22 |
| tetryl | 1.28 |
| Comp B | 1.33 |
| PETN | 1.42 |
| RDX (hexogen) | 1.60 |
A grenade’s fuse is the most critical component in regards to safety and reliability. While grenades are comparatively simple munitions, their fuses can be quite complex. They include: safety and arming pins; arming levers; covers; spring-loaded firing pins and strikers; arming plungers and setbacks; igniters; primers; delay fuses (delay train); flash tubes; detonators; booster or bursting charges; and starter compounds – assembled in a functional housing to hold it in the grenade. Grenades are fitted with some form of delay-train fusing, usually 4–6 seconds plus or minus a half-second. A 15 percent timing tolerance is customary. The delay must be long enough to ensure the grenadier’s safety and allow it to be thrown to the maximum range, but not so long a delay to allow the enemy to return it.
During World War II, an SS-Oberscharführer of Nazi Germany’s Waffen-SS inserts the No. 8 detonator into the upper end of the handle of an Stg 24. The cord attached to the friction igniter with its porcelain ball dangles from the handle’s lower end. The cord and ball will be inserted into the handle and the metal end cap screwed on. (Tom Laemlein/Armor Plate Press)
The lever-release fuse is activated by pulling an arming pin, a cotter pin, and releasing a safety lever, AKA “spoon.” It detonates after a set time initiated by the activation of a “mousetrap” striker hitting a primer and igniting the delay train. Originally a World War I French design, it is commonly called the “bouchon-type” igniter, a term derived from the French M1916B automatic igniter (bouchon allumeur automatique). Bouchon means plug or stopper, describing the fuse as fitting in the top of the grenade as a plug in a bottle. Since World War II this has become the most widely used fuse. A second type of lever-release fuse uses a spring-loaded firing pin in a vertical tube-like housing. It is held in the cocked position by the arming pin. When pulled, the end of the arming lever continues to retain the firing pin. When the lever is released, the pin plunges downward to strike the primer. The pull-igniter fuse has a cap that is unscrewed to expose the pull-igniter – a ball or ring on a cord. It is pulled and the match-like friction igniter activates the delay train. This type of igniter has a high failure rate owing to the igniter failing to light the pyrotechnic – no second pull is possible. It is highly susceptible to moisture. The percussion-igniter fuse has an arming pin that is removed to free an internal firing pin. The fuse is sharply rapped on a solid object (helmet, boot heel, rifle stock, rock), releasing the firing pin to strike a primer and igniting the delay.
In contrast, the impact-detonated grenade does not have a delay fuse. An arming pin is pulled and a safety lever or cap released when thrown. This arms an “all-ways” impact fuse, which instantaneously detonates when it impacts. Such weapons were unpopular because if accidentally dropped they immediately exploded or exploded within lethal range of the thrower if striking nearby vegetation. They were unreliable and did not always detonate upon impact, resulting in sensitive, armed duds. Due to their danger and questionable reliability, they saw little use. At different times there have been attempts to develop safe, reliable impact-detonated fuses, but they remain dangerous.
The following grenades are examples of the hundreds of models fielded over the past century. The descriptions focus on antipersonnel grenades, but include examples of some of the more notable other types.
The British No. 1 Mk I percussion pattern grenade. Monsieur B. Pedersen of Belgium had patented a rod-type rifle grenade in 1905. This influenced a design by Marten Hale of Britain, patented in 1908. The Royal Laboratory at Woolwich Arsenal undertook to develop a similar grenade while avoiding patent fees. 22in long, the new grenade was similar in design and functioning as Hale’s rifle grenade, but the No. 1 Mk I was hand-thrown. As it was necessary for the rifle grenades to impact nose first, the No. 1 hand grenade had a 16in cane handle with braid stabilization streamers, but the handle made it dangerous to throw, owing to the high probability of the impact-detonated grenade striking a trench’s parados (rear parapet). Some troops refused to use it, or even the shorter handled (8.5in) No. 1 Mk II. (Treatise on Ammunition, British, 1915)
The British developed scores of antipersonnel grenades, but only the most widely used are addressed here. Commonwealth nations used British grenades and often produced them. When the British Expeditionary Force (BEF) arrived in France in August 1914, it was prepared for mobile warfare, not for troops peering across tangled barbed wire and a cratered sea of mud. There was a sudden rush to develop trench-warfare weapons. Hand grenades were among these. The BEF did possess a grenade, the No. 1 Mk I percussion-pattern grenade, adopted in 1908. Besides being slow to produce, it proved dangerous. Since it was armed after the pin was pulled and impact-detonated, the grenade exploded when it struck an object. When held by the long handle and the arm swung back to throw, it could strike the trench’s rear parapet. This led to a general refusal to use them. The No. 1 Mk II had an 8.5in handle and other improvements, but it still met with accidents. By the end of 1914 production had reached 70 grenades per week, enough for a single trench raid. It is no wonder that “trench-made” grenades were produced by the troops, a dangerous undertaking in both manufacture and use. According to one “recipe”: “Take a jam-pot, fill it with shredded guncotton and ten penny nails, mixed according to taste. Insert a No. 8 detonator and a short length of Bickford’s Fuze. Clay up the lid. Light with a match, pipe, cigar or cigarette, and throw for all you are worth” (quoted in Holmes 2005: 386).
A No. 5 Mills Bomb, manufactured in September 1915. The Mills’ body had a small filler hole near the top and a sparking-prone percussion fuse inserted from the base and secured by a base plug. The fuse consisted of a vertically aligned tube containing a spring-loaded striker. When the arming pin was pulled and the grenade thrown, the striker lever flew off, releasing the striker. It struck a cap on the end of a J-shaped delay fuse. The igniter set consisted of a cap, cap chamber, delay fuse, and No. 6 detonator. This was the common design for all marks with minor differences. No. 5 production ceased in March 1918. (© IWM MUN 3207)
The scene shifts to Belgium where in early 1914, Albert Dewandre of Compagnie Belge de Munitions Militaire and Capitaine Léon Roland of the Belgian Army co-designed a grenade with an automatic fuse igniter activated when an arming pin was pulled. It also incorporated an arming lever for further safety. The delay train and detonator were contained inside the grenade. Roland was taken prisoner in November, leaving Dewandre to press on with the grenade’s continued development. The resulting Roland grenade was a segmented sphere. It was complex and expensive, with multiple internal chambers for the involved fusing system. It also had fragmenting segments cast inside, which was unusual. In January 1915 William Mills, the innovative owner of two metal-forging plants, made arrangements with the British War Office to fabricate four Roland grenades and help evaluate them. On January 26, Dewandre armed and threw the grenades, which failed to function properly. The War Office rejected the Roland as unreliable and unsafe. Mills further developed the design and produced drawings in early February. The first proposed design was cylindrical rather than the Roland’s sphere or the oval shape later adopted by Mills. It had external segmentations, but Mills stated they served to provide a firm grip with wet or muddy hands. Prototypes were tested on February 20, 1915. With a few modifications, the Mills Bomb was soon in mass production. Roland had applied for a patent in Britain in August 1913 and it was accepted in December that year. Mills’ patent application was filed in February 1915 and accepted in December. After the war there were subsequent patent disputes, which were never fully resolved. Even so, the Mills Bomb is considered the longest-serving grenade anywhere in the world, seeing use into the 1990s, and may still be encountered.
The first orders for 50,000 Mills Bombs were placed with Mills Munitions Ltd and two other firms in late March 1915. Eventually, 20 other companies produced the 75 million Mills Bombs of all marks supplied to the British and Allied armies. A small batch was sent to France for combat testing in March, and larger numbers were available by May. It was not until September 1915 that significant numbers were arriving at the front, in time for the battle of Loos. The demand for grenades was so great that “trench-made” grenades remained in use and the War Office accepted other models, not only to supply the vast numbers needed, but always in search of more effective and safer models. The Mills Bomb retained its reputation and became the standard grenade after the war.
The first Mills Bomb was the No. 5 Mk I, approved in May 1915. The No. 23 Mk I, offering minor refinements, began production in July 1916. The No. 23M Mk I had improved sealing and explosive fillers better suited for storage in the tropics. “M” referred to Mesopotamia, a hot-wet tropical region in Iran and Iraq. The No. 23 Mk II and No. 23M Mk II had additional improvements to the fuse. The No. 23 Mk III and No. 23M Mk III were substantially redesigned, having a larger filler hole slightly lower on the body, a recess for the arming lever, differently shaped lever brackets, and the base plug redesigned for improved tightening, plus additional improvements to the fuse and sealing.
The No. 36 Mk I was introduced in May 1918, a slightly modified No. 23 Mk III. The fusing was improved and changes made to speed manufacture. 4in high and 2.4in in diameter, it remained standard until December 1923. The No. 36M Mk I had been introduced in March 1918. In 1923 it was decided that all grenades should be better sealed and contain explosives better suited for long-term storage in any climate. The No. 36M Mk I became the standard Commonwealth grenade, simply known as the “No. 36.” The main difference between the No. 36 and 36M and the No. 5 and 23 was that a 2.5in-diameter Mk I “gascheck” disc could be screwed into the base plug for the later two models. This allowed it to be launched from the 2.5in No. 1 Mk I grenade discharger on the Lee-Enfield rifle, AKA the “E.Y. discharger” – Edward Yule was the designer. The No. 36M, while remaining in use, was no longer used as a rifle grenade after 1945, but not declared obsolete as such until 1962.
The Mills was 4.75in long and 2.3in in diameter. It weighed over 1.5lb, with just over 2oz of explosive: alumatol, ammonal, amatol, Bartol, Bellite, Cilferite, Sabulite, or Trotyl. The bodies were shellacked brown inside and out to prevent rusting and chemical reaction with certain explosives. Amatol-filled grenades had a green band around the body and grenades filled with alumatol, ammonal, or Bellite had a pink band. All had a red band around the top, indicating they were filled. All Cilferite-filled grenades were destroyed at the end of 1932 as unsafe and from 1936, Trotyl was no longer used. Post-war Pakistani grenades were filled with TNT. No. 36 grenades were painted service brown (dark brown). No. 36M grenades had a row of red Xs in lieu of the red band.
The No. 5 and 23 grenades both had 5-second delays, to include the No. 23 when launched from a rifle. The original No. 36 and 36M had 7-second delays when used either as a hand or rifle grenade. Gaschecks and discharger cartridges were packed with the grenades. In 1940, the BEF in France complained that this long delay allowed the enemy to throw grenades back. From 1941, 4-second igniter sets were issued in the boxes for hand-thrown grenades while 7-second sets were issued along with gaschecks for grenades intended for firing from dischargers. These could still be used as hand grenades if necessary. The boxes were marked “Hand Grenades 4 secs” or “Discharger Grenades 7 secs.” No. 36Ms were made in India with instantaneous detonators for use as booby traps. The detonator set was painted red and the top of the cap chamber was knurled so it could be identified at night. A tag stated “This grenade MUST NOT be fired from a rifle or thrown by hand.” Australia fielded the blast attachment Mk I and blast bomb Mk II, cans almost twice the size of the No. 36M filled with TNT and ammonal, respectively, and attached to the bottom of grenades for attacking fortifications.
1. Striker
2. Safety pin
3. Base plug
4. Mk I gascheck disc (for use as a rifle grenade)
5. Cast-iron body
6. Safety lever
7. No. 27 detonator
8. 22-caliber percussion cap
9. No. 17 fuse (7-second delay)
10. Ammonal, alumatol, amatol, or Cilferite filling
11. Filling-hole plug
No. 36M grenades were employed by all Commonwealth forces in World War II, Korea, Malaya, Borneo, and other conflicts. They were used by Free Polish forces in France and Italy. Some have turned up in Iraq and are still encountered in remote parts of the world. Many were supplied to French, Italian, Yugoslavian, and other partisans by the Special Operations Executive, while the German Abwehr provided them to its own saboteurs in Italy. It was produced by Britain, Australia, Canada, India, New Zealand, and South Africa. British and Australian production continued until 1972. They were still being made in India and Pakistan at least into the 1980s as well as Indonesia. Former UK protectorates continued their use long after the war. They were used by Australian forces until 1976 but not in Vietnam, where the “Diggers” were armed with US grenades. Mills were used by Ireland and various African, Middle Eastern, and Asian countries. Owing to grenade shortages in Papua during the battle of Buna–Gona (November 1942–January 1943), US troops were issued Australian No. 36Ms to make up for shortages of their Mk II grenades (see below). In an early 1943 survey, 78.6 percent of US 32nd Infantry Division soldiers preferred the Mills over the Mk II owing to its more powerful blast. The Mills had 2.437oz of filler while the Mk II had 1.85oz. The Mills also fragmented more effectively. Casualty radius was about 20yd, with large fragments traveling up to 100yd. A Mills detonated in a test chamber generated almost 500 fragments, ranging from tiny bits to inch-long shards.
A collection of hand grenades along with 40mm under-barrel grenade-launcher rounds to be issued to a British section (squad) in Afghanistan, 2007. The larger, light-green grenades are L70A1 red signaling smoke grenades. Other colors are L68A1 green, L69A1 orange, and L71A1 blue. The smaller, dark-green grenades are L84A1 red-phosphorus screening smoke grenades. Red phosphorus is safer than white phosphorus and also burns white. The spherical grenades are L109A1 fragmentation grenades, based on the US M67. (© IWM HU 104270)
Complementing the F1, the OF M1915 offensive hand grenade with an M1916B fuse was used during World War I and early in World War II. It had a thin, stamped-steel body and no fragmentation liner, and could be fitted with the same fuses as the F1. Filled with 150g (5.29oz) of Cheddite, it weighed 250g (8.82oz). Being lighter than the F1, it could be thrown farther. The example shown here is blue-gray in color, as used during World War I. Later examples were all yellow. (© IWM MUN 3224)
France began World War I with one official grenade: the M1847, a pig-iron spherical grenade, 81mm (3.19in) in diameter, with an “undated” wooden-bodied friction igniter employing black powder. The M1847 weighed 1.2kg (2.65lb) and had a 5-second delay. The M1914 had a somewhat improved metal friction igniter and weighed 1kg (2.20lb). The Munitions Service produced various crude, field-expedient grenades, which proved largely unsafe. Adopted in May 1915, the P1 (percutante n°1, or “impactful no. 1”) was known as the poire grenade (“pear grenade”). Weighing 550g (1.21lb), it was one of the first grenades with a spoon-like arming lever. It had a percussion igniter and was impact-detonated, if it landed base first on sufficiently hard ground. The mud of no man’s land often caused failure to detonate or dampened the blast. Premature detonations were common and even though it was one of the few grenades with internal segmentations, its break-up was poor. The P1 was invented by a Monsieur Billant, who developed the more successful M1916B percussion fuse that was to set the standard for grenade fuses.
A more effective and safer grenade was also introduced in May 1915, the F1 (fusante n°1 – “fusing no. 1” – or grenade à main defensive F1 – “F1 defensive hand grenade”). It is difficult to say if it was fielded before or after the British Mills Bomb (see above). Several different types of fuses were used on the F1. The bouchon allumeur à mèche (plug wick igniter) was fitted on the earliest F1s. The M1915 percussion plug igniter (bouchon allumeur à percussion M1915) consisted of a percussion igniter held in a small cardboard tube; it had to be struck on a hard surface to ignite the delay fuse. This was protected by a removable, sealed cardboard tube, 60mm (2.36in) long and 12mm (0.47in) in diameter. It was far from waterproof and the long fragile “protective” tube and the percussion igniter tube were easily damaged. A somewhat improved M1916 percussion plug igniter (bouchon allumeur à percussion M1916) consisted of a shorter brass tube containing the percussion igniter with a shorter brass protective cap. This was less susceptible to damage and more resistant to moisture. It still experienced reliability problems and was not sufficiently waterproof. In 1916 Monsieur Billant developed the M1916B automatic plug igniter (bouchon allumeur automatique M1916B). All fuse delays were 5–7 seconds. As with other segmented-body fragmentation grenades, the F1 did not break up according to the segments, nor did it shatter into a great many smaller fragments. It was not uncommon for it to break up into only ten or so fragments. Casualty radius was 20m (22yd), with a 75m (82yd) danger radius. During World War I the F1 was painted blue-gray. From the early 1930s it was painted reddish-brown.
1. Safety cap
2. Arming tape (11.5in long) with lead weight
3. Bakelite body
4. Base-hole plug
5. Filling-hole plug
6. Lead activating ball
7. Safety bolt
8. Striker
9. Primer
10. Detonator
11. Amatol, baratol, or Lyddite filler
1. Arming lever
2. Arming pin
3. Sheet-metal body
4. Primer
5. “Mousetrap” striker and spring
6. 3.9–4.9-second delay element
7. Detonator
8. RDX/TNT filler
9. Pre-scored fragmentation liner
10. Pre-scored fragments on base plug
Adopted in December 1940 and remaining in service until 1947, the No. 69 Mk I offensive grenade – “Bakelite” or “assault grenade” – generated virtually no fragmentation because of its frangible Bakelite body. It caused little material damage, relying on blast and flash to injure and unnerve the enemy. Its No. 247 all-ways impact fuse was on the top with the detonator in the bottom. The 13.5oz grenade was filled with 3.25oz of amatol, baratol, or Lyddite (picric acid). It was also made in Australia, of dark reddish-brown Bakelite. The No. 69 was also used as a training grenade; for this purpose it was thrown only behind advancing troops to simulate artillery and was to be detonated no closer than 30yd. Its use during night exercises was restricted because of its blinding flash and the danger of throwing it near unseen soldiers. This practice was halted when casualties resulted from the fuse’s lead ball.
The L2A1 antipersonnel grenade, shown here with the L25A6 fuse, was essentially a 1964 copy of the US M26A1 (see below) with differences in the fuse – the most noticeable being a 3.6–5.5-second delay, rather than the M26A1’s 4–5 seconds. The L2A2 involved manufacturing improvements. A product-improved version, the Royal Ordnance RO 01A1, has replaced these; it is bronze green with yellow markings.
OF37 offensive (above) and DF37 defensive (below) hand grenades with M1935BG lever-delay fuses. These pre-World War II grenades are still in use today with modernized fuses. They were employed in Indochina/Vietnam, Algeria, and later conflicts, with wide use throughout Africa. The bodies of World War II-era OF37 and DF37 grenades had a yellow upper half, while the color of the lower half was dependent upon the explosive: yellow (TNT); green (Cheddite or Lyddite); or brown-red (Schneiderite, amatol, or ammonium nitrate/xylite). (Author)
While the F1’s performance was far from ideal, it proved popular and was one of the most widely used French grenades in World War I. After the war all other fragmentation grenades were retired and improved explosive fillers introduced, causing more effective fragmentation. While replaced by the much-improved Mle 37 grenades (see below), F1s were still in use at the beginning of World War II. They continued to be used by the Vichy French in Metropolitan France and North Africa and of course in overseas colonies including Indochina. The Japanese used some in Southeast Asia and German troops employed them in France. France sold some to Finland during the 1939–40 Winter War. They were provided to White Russian forces during the 1917–22 Civil War and were also used by Poland during the 1920s border clashes with the Soviet Union. The F1 served as a model for other countries’ grenades, influencing the Polish wz. 33, US Mk I and Mk II, and Soviet F-1, from which other F1 spin-offs were derived (see below).
The French adopted two new grenades in 1937, the OF37 offensive and DF37 defensive hand grenades (Grenade à main offensive OF M1937 and Grenade à main defensive DF M1937). Both had oval bodies with flat bottoms. They have used the M1931BY or M1935BG 5-second lever-delay fuses. The OF37 blast grenade has a thin aluminum body with a circumference rim allowing night identification. The DF37 fragmentation grenade has a cast-iron body. Height is 95–105mm (3.74–4.13in) depending on fuse; the OF37 is 60mm (2.36in) in diameter and the DF37, 55mm (2.17in). Several different types of filler were used, but post-World War II grenades have TNT. Newer grenades have OD bodies, with those manufactured by Ruggieri using the M F3 fuse similar to earlier models. Those made by Alsetex use the M F5A pyrotechnic delay fuse.
The beginning of World War I found the Germans somewhat better equipped with grenades than their enemies. Even so, “trench-made” – Behelfs (‘improvised’) – grenades were necessary to supplement issue grenades. These were mainly made from ration tins or were of the “hairbrush” type. The first issue grenade was the Kugelhandgranate 13 (“ball hand grenade 1913”), a deeply segmented spherical grenade with a friction igniter. Other than the segmentations (for a better grip), it was little different from 19th-century grenades. An improved fuse and simplified casting requirements resulted in the Kugelhandgranate 15. Both were heavy, at 1kg (2.20lb), and packed with 45g (1.59oz) of explosive. Complaints of 15m (16yd) throwing ranges eventually led to lighter grenades. The Eierhandgranate 17 (“egg hand grenade 1917”) appeared in early 1917. 60mm (2.36in) long and 46mm (1.81in) in diameter, it had a smooth cast-iron body and friction igniter. It weighed only 318g (0.70lb) with a 32g (1.13oz) filler. A new type was issued in late 1917, featuring an improved fuse and a segmented band around the circumference to provide a firmer grip.
1. Cast-iron body
2. Fuse holder and plug
3. Protective cap
4. Percussion cap
5. Friction igniter
6. Brass igniter prongs
7. 5-7-second delay fuse
8. Cheddite, Schneiderite, or amatol filling
9. Detonator
1. Belt hook
2. Wooden throwing handle (delay marked on handle)
3. Friction-igniter pull-loop secured by paper band
4. Friction-igniter pull-wire
5. Friction-igniter tube
6. 5.5- or 7-second-delay fuse holder
7. Detonator
8. Ammonium nitrate or tolite filler
The French F1, shown here with the M1915 fuse, soon became known as la citron (“lemon”) due to its shape or the ananas (“pineapple”), because of its deep segmentations, and grenades quadrillées (“square-patterned grenades”) owing to the segmentations. The F1 – and its fuse, very advanced for the time – would have a great deal of influence on grenade design in spite of its marginally effective fragmentation. The cast-iron body was 90mm (3.54in) long without a fuse and 55mm (2.17in) in diameter. Weight was approximately 710g (1.57lb) depending on the type of fuse. In the top was the fuse well with a filler hole in the bottom. At first the F1 grenades were filled with Cheddite and later Schneiderite, amatol, or nitrate-xylite – ammonium nitrate-based explosives.
The German Stielhandgranaten of World War I all had thin-walled steel cylindrical heads with a belt clip; they were typically 105–120mm (4.13–4.72in) long and 72mm (2.83in) in diameter on a wooden handle 240–260mm (9.45–10.24in) long. They weighed about 820g (1.81lb) with a 270g (9.52oz) filler, either ammonium nitrate or – from 1916 – more powerful tolite. Most delay fuses were 5.5 seconds, but some had 7-second delays. Delay time was marked on the side of the head.
The Diskusgranate had a diameter of 105mm (4.13in) and a height of 30mm (1.18in). Requests from the front asked for a grenade that could be thrown farther than the ball grenade and was impact-detonated. The resultant grenade was a convex disc containing six tubes arranged in a star-like pattern. These contained a complex arrangement of firing pins, sliding tubes, and a detonator. When thrown, a spin was imparted on the grenade, as with throwing an actual discus. They could reach up to 50m (55yd). Centrifugal force slid the internal tubes to uncover four firing pins. Upon impact, one or more of the firing pins struck the primers in the center and fired the detonator. It was armed by pulling an arming ring on the edge. (© IWM MUN 3221)
The improvised “hairbrush” grenades were thought to achieve greater range and accuracy. This led to a series of Stielhandgranaten (“stick hand grenades”), with the first appearing in 1915. The main differences between models were improved, more reliable fuses and better waterproofing. Most had friction pull-initiated fuses with a detonator in the base of the head where the handle fitted. The handles were bored with a pull cord. In 1916, versions were adopted with a threaded cap on the handle’s end to protect the pull cord and prevent water from entering the pull-cord hole. Two new types appeared in 1915, both percussion-impact grenades, and a further-improved model in 1916. These were armed by pulling an arming ring on the handle and throwing them so they would impact head-first. To improve safety, a “spoon” or lever was fitted to the handle. The ring was pulled and when the grenade was thrown the spoon flew off, arming the grenade. As with most impact-detonated grenades, they were none too popular and often failed to detonate in mud or landed on their side.
One of the more unusual types of grenade during World War I was the Diskushandgranate 15 (“discus hand grenade 1915”). This 420g (14.82oz) grenade was considered an offensive grenade. It was used as a booby trap by pulling the pin and balancing it, for example, on the top of a door. When the grenade fell it detonated on impact. It was small enough, 105mm across, 30mm thick, to push through a tank’s vision slits. Weighing 360g (12.70oz), the less common and smaller 1915 Eierhandgranate (“egg hand grenade”) had thicker walls with internal segmentations to improve fragmentation. Besides standard German antipersonnel grenades, dozens of expedient grenades were fielded during World War I’s final months in a wide variety of materials including concrete and wood.
The Stg 24 (Stielhandgranate 24, or “stick hand grenade 1924”) was the commonest German grenade during World War II and derived from various World War I models of “potato-mashers” (Kartoffelstampfer). It consisted of a field-gray steel head with a hollow wooden handle containing the fuse and detonator. The pull cord was inside the handle protected by a screw cap. The handle’s end cap was unscrewed and a porcelain bead pulled to initiate the 4.5-second delay train. Slip-on fragmentation sleeves were introduced in 1942. The 14in-long grenade contained a 6oz TNT or black-powder (substitute) charge. The NbHgr 39 (Nebelhandgranat 39, or “smoke hand grenade 1939”) was similar to the Stg 24, but generated white smoke.
1. Protective cap
2. Protective ears
3. Metal case
4. Carrying ring
5. Add-on fragmentation sleeve
6. Friction-igniter pull-cord
7. Friction igniter
8. 4.5-second black-powder delay element
9. No. 8 (A1) detonator
10. TNT or Donarit (ammonium nitrate) filler
1. Arming pin
2. Arming lever
3. Plastic fragmentation sleeve
4. Primer
5. “Mousetrap” striker and spring
6. 4.5-second delay element
7. Detonator
8. Booster charge
9. Nitropenta filler
The World War II-era Eihgr 39 nA included protective steel “ears” on the fuse and the carrying ring on the bottom, both added in early 1942. A two-piece fragmentation sleeve was fielded from September 1944, but saw little use. The egg grenade contained either 112g (3.95oz) of TNT or 225g (7.94oz) of Donarit (commercial ammonium nitrate). To arm it, the blue fuse cap was unscrewed and pulled to start the 4.5-second delay. For use as a booby trap, 1-second delay igniters with a red cap were provided with this grenade; when Allied soldiers attempted to use these, they detonated when the cord was pulled.
Developed by Diehl Defense, the DM51 is a dual-purpose grenade consisting of a small plastic cylinder containing 60g (2.12oz) of Nitropenta with a DM82A1 lever-release fuse (3–5-second delay) as a blast grenade. It has a safety clip, and is issued with a double-walled oval body with flat ends that the blast grenade slips into, secured by a twist-lock. The ribbed plastic body contains 6,500 steel ball bearings. It is 107mm (4.21in) high and 57mm (2.24in) in diameter.
The Stg 24 (Stielhandgranate 24 mit Brennzünder 24, or “stick hand grenade 1924 with igniter fuse 1924”) was Nazi Germany’s most widely used grenade. It remained in use with the forces of some European countries into the 1950s. This is a cutaway instructional grenade. The “potato-masher” (Kartoffelstampfer) or “doorknocker” (Türklopfer) became an iconic symbol of the German infantry. (Public Domain)
A widely used grenade was the Eihgr 39 (Eihandgranaten 39, or “egg hand grenade 1939”). This 9oz blast grenade was approved in April 1940. It was lighter, and faster and quicker to manufacture, than the stick grenade; more could be carried, and they could be thrown farther. There were also little-used 7.5-second delay fuses with a yellow cap and a 10-second with a white cap. The Eihgr 39 nA (Eihandgranaten 39 neuer Art, or “egg hand grenade 1939 new type”) was also widely used. Besides smoke screening, the Germans employed smoke grenades to blind tanks and allow close-in infantry attacks. The Stg 43 (Stielhandgranate 43) was a Stg 24 substitute with the Eihgr 39’s fuse fitted atop the head and a solid-wood handle.
German-designed grenades reappeared in the West German armed forces in the 1970s. The DM51 Spreng/Splitterhandgranate (“blast/fragmentation hand grenade”) was adopted in 1978, replacing the DM41 Splitterhandgranate, the US M26A1. It is supplemented by the DM61 fragmentation hand grenade, also a Diehl design, with a double-walled pear-shaped plastic body containing 6,000 ball bearings, each 2mm (0.08in) in diameter. 103mm (4.06in) high and 57mm (2.25in) in diameter, it contains 65g (2.29oz) of Nitropenta and a DM82A1 fuse, and provides 5 percent better fragmentation uniformity than the DM51. It is also used by Norway.
The Mod. 23 petardo offensive (“offensive petard”) was a 400g (14.11oz) blast grenade 120mm (4.72in) long and 80mm (3.15in) in diameter. It was activated by a percussion fuse and had an all-ways impact fuse. The “P.O.” was used by Ecuador during the Zarumilla-Marazñón Border War with Peru in July 1941. It may have seen limited use in the Spanish Civil War and early in World War II. The MCS hand grenade had an all-ways impact fuse and was adopted in the late 1920s. It had a cylindrical body with truncated cone-shaped ends. Its two-piece body screwed together at the mid-section with a separately contained explosive chamber. It was armed by pulling a ring that withdrew an arming strip, blocking the firing pin, and holding down a large safety ring that encircled the upper part of the body. When it was thrown, the safety ring fell off and the fuse was armed.
The “S” hand grenade was a small, offensive, blast grenade and was the first Italian grenade with an all-ways impact detonator. Its two-piece, egg-shaped body screwed together at the mid-section. Introduced in the late 1920s, it was withdrawn from use during the Spanish Civil War as the sensitivity of the fuse made it dangerous to the thrower. A safety pin was pulled while holding down a safety band that encircled the grenade. The band fell free when thrown and the impact fuse was immediately armed, making it extremely hazardous if dropped by the grenadier. The meaning of the “S” is unknown.
The SRCM Mod. 31 hand grenade was similar to the above MCS grenade and intended as an improvement. It was of the same shape, but with small projections on both ends. Rather than a ring on the arming strip it had a pull tab, which was used on most subsequent Italian grenades. Besides the safety ring it also had a safety cover attached to the ring, making it easier to retain before throwing. The inner explosive chamber had a thin, segmented fragmentation sleeve. Short, free-floating metal tubes on each end of the inner explosive chamber fit into the outer body’s end projections and held the change in place. Upon impact, the explosive chamber was knocked loose, regardless of the angle of impact, to release the spring-loaded firing pin and detonate the grenade. The Czechoslovak RG-34 hand grenade was copied from the SRCM Mod. 31.
100mm (3.94in) long, 65mm (2.56in) in diameter, and weighing 630g (1.39lb), the Besozzi grenade was provided to French forces in early 1915 and later produced in France under license. It appeared similar to the Mills Bomb, but had an unsegmented band around the body, which consisted of two halves that screwed together and provided poor fragmentation. A friction match-head was molded onto the 5-second time fuse inserted in the top. (© IWM MUN 3223)
From the mid-1930s Italy made extensive use of three different Mod. 35 hand grenades (bombe a mano mod. 35) of vaguely similar design, but made by three different manufacturers. The manufacturers’ initials were included in their designations to differentiate them. The reason three manufacturers’ variants were used was to allow rapid stocking to support the government’s aggressive aims. The Breda Mod. 35 hand grenade (Bomba a mano Breda modello 35) was not as effective as other Mod. 35s owing to its light blast, but the Breda model was one of the most widely used of the three because of Breda Meccanica Bresciana’s production capacity. The body had five lateral, raised corrugations and both ends were shaped as a truncated cone, with a hemispherical safety cover. When the safety strip was pulled out and the grenade thrown, the safety cover fell free, pulling a brass strip which was wound around the head twice. This strip was attached to the safety device and was pulled out to arm the fuse when the cap and strip fell away. The heavy head held the firing pin, which detonated the grenade upon impact. With red body and black safety cover, the Breda Mod. 35 was 96mm (3.78in) long and 58mm (2.28in) in diameter.
The OTO Mod. 35 hand grenade (Bomba a mano OTO (Oto Melara SpA La Apenzia) modello 35) was the smallest Mod. 35 and considered the most reliable, but produced few lethal fragments and a light blast. It had a cylindrical body containing a separate explosive chamber and a smaller-diameter upper section shaped as a truncated cone. When the safety pin was pulled the safety cover was freed. The cover fell free when the grenade was thrown, pulling out the safety strip. A metal ball filled with lead shot was contained in the upper section. Upon impact the ball was driven into the firing pin to detonate. The lower half of the body was red while the upper half was unpainted aluminum; it had a black safety cover and was 86mm (3.39in) long and 53mm (2.09in) in diameter.
Italian impact-detonated “Red Devils”: (left to right) The OTO Mod. 35 was considered the most reliable; the SRCM Mod. 35 had a heavier explosive charge and fragmentation liner; and the Breda Mod. 35 was the most widely used, but least effective of the “Red Devils.” Each was operated by pulling a rubber arming tab (allowing it to be pulled by the teeth), which withdrew a safety strip, and allowed the safety cover to fall free when thrown. Upon impact, some form of firing device drove the firing pin into the detonator to detonate the TNT. They were only moderately effective owing to their stamped-aluminum bodies providing minimal fragmentation. Casualty radius was 4m (4.5yd) for all makes except the SRCM, with 8–14m (9–15yd). Mixed batches of makes were habitually issued to units. (US Army)
The SRCM Mod. 35 hand grenade (Bomba a mano S.R.C.M. (Societá Romana Costruzioni Meccaniche) modello 35) was the only Mod. 35 with a fragmentation liner and had a heavier explosive charge, but its fragmentation effect was limited. It contained an explosive chamber with a detonator separated from the fixed firing pin by a spring. The explosive chamber was wrapped with twisted wire for fragmentation. When it was thrown, the safety cap fell away, pulling a small chain that pulled out the safety strip. Upon impact the explosive chamber’s detonator was driven into the firing pin. Commonwealth troops removed the fuse assembly and explosive charge and modified the grenade body into a dugout oil lamp. Its production continued until 2012. It was 80mm (3.15in) long and 64mm (2.52in) in diameter, and was initially distinguished by its red body and safety cover in unpainted aluminum.
After World War II, the grenade had an OD body but retained the unpainted aluminum safety cover. To replace the SRCM Mod. 35, the OD-82 (Offensiva-Difensiva) was adopted in 1982. It body was 59mm (2.32in) in diameter and 83mm (3.27in) high. The 285g (10.05oz) grenade had a 112g (3.95oz) Comp B charge, making it effective as both a blast and fragmentation grenade. The original 4-second fuse occasionally detonated early and an improved fuse was adopted in the mid-2000s. It has a large arming lever and a pull-type arming tab. Early grenades were colored gray, while late grenades are olive drab, both with yellow bands.
Since World War I the United States has essentially used three models of fragmentation grenades, all of which have been employed by numerous other countries. The United States adopted a cylindrical hand grenade with a throwing sling in 1911. It never saw combat. Within days of the US declaration of war on Germany (April 2, 1917) the Ordnance Department’s Trench Warfare Section was established to oversee grenade development and production. The Trench Warfare Section, after examining French and British grenades, was determined to develop the simplest, safest, and most effective grenade. The design of the Mk I defensive hand grenade was completed in August 1917 and mass production commenced soon after. In the effort to design the safest-possible grenade, however, the Mk I proved overly complicated. It was too much to expect of a soldier under the stress of combat and possibly with cold hands in rain and mud to manipulate it correctly. Some were thrown without the lever having been turned. This prevented its detonation and allowed the enemy to return it. Over 23 million grenades would be produced by the war’s end, but on May 9, 1918, the American Expeditionary Forces (AEF) sent a cablegram rejecting the Mk I as too complicated and unsafe.
To throw the US Mk I grenade, the thumb was placed against the lever and the pin pulled. The lever was pivoted to one side when the grenade left the hand. This allowed the fuse cover to fly off, releasing the spring-loaded striker to ignite the delay train. It was more problematic with the underhand throw, as it was difficult to pivot the lever with the thumb. The pin was pulled and the lever rotated, allowing the cover to fall off – sometimes it had to be shaken off. It could arm while still in the hand. Either way, it had to be gripped correctly, with the thumb laid precisely in position and the thrower coordinated enough to thumb the lever properly when thrown. The Mk I’s body was similar to the French F1’s, but a higher-grade malleable iron was used. It was slightly more powerful, with 2oz of TNT or 50/50 amatol and nitro-starch. Body production went smoothly, but the chief concern was the “bouchon” fuse, which was also rather expensive. The Mk I 5-second delay fuse had a separate top cover on the fuse housing and a pivoting arming lever that was fixed to a downward-angled projection on the fuse housing’s bottom. The lever was creased down the center to provide a U-shaped bar – not the later thin, flat lever. It was fixed to the projection by a screw on which it pivoted. (Tom Laemlein/Armor Plate Press)
The Mk I’s successor, the Mk II “pineapple” defensive grenade, would see almost 50 years’ service. Plans for the Mk II defensive grenade were ready on August 1, 1918 and new machinery had been installed. Existing Mk I bodies could be used, but new fuses had to be produced. The Mk II “bouchon” fuse was totally redesigned, being more similar to the French M1916B. The fuse cover and level were now one piece and the lever pivot was omitted. Some 44 million were ordered and well over 21 million completed by the war’s end. Few reached France. Refinements were made after the war and the new Mk II high-explosive hand grenade was adopted in 1920. The M5 fuse was easier to manufacture and improved for reliability and safety. Mk II HE grenades were still in use at the beginning of World War II. From 1920 Mk II bodies were painted yellow as a cautionary warning and to help locate duds during training. 4.5in long and 2.3in in diameter, the Mk II was normally filled with 1.85oz TNT, but owing to shortages, some early examples were filled with 2.33oz Trojan explosive, while others were filled with 1.85oz of amatol 50/50 or more sensitive Grenite. In 1930, minor changes were made to the Mk II to accommodate refinements in production techniques, and “HE” was dropped from the designation. Its color, characteristic shape, and segmented body led to its nickname, the “pineapple.” It was just as widely known simply as the “frag.” Mk IIs were also filled with 0.74oz EC blank fire powder, which was used in blank ammunition and designed to create high pressure even unconfined.
A US Marine Corps ordnance technician spray-paints formerly yellow Mk II fragmentation grenades OD in 1943. It was discovered on Guadalcanal in late 1942 that the yellow color helped the Japanese find grenades at night and they threw them back or took cover. Yellow was also conspicuous when grenades were hung on web gear. Prior to 1943, all HE munitions were yellow and then repainted OD. In 1943 they began to be painted OD instead. The Office of Strategic Services, a precursor of the later Central Intelligence Agency, requisitioned Mk IIs with zero-delay fuses for use as booby traps with tripwire and tape in each container. The container and arming handle were secured with red tape warning of immediate detonation when the handle was released. A red metal tag on the pull ring offered the same warning. Some of these were used in Korea by UN partisan forces. More Mk IIs and Mk IIA1s were produced than any other hand grenade in World War II. They were supplied to the Free French, Nationalist Chinese, and various partisan forces. The Mk II body was used for the warhead of the 1942 M17 fragmentation rifle grenades. Two bodies fitted in tandem were tested as an antipersonnel rocket for the 2.36in bazooka. (Tom Laemlein/Armor Plate Press)
Ethiopian soldiers of the 3rd Kagnew (Conquerors) Battalion attached to the 32nd US Infantry Regiment, 7th Infantry Division in Korea. Each carries a newly issued M26 fragmentation grenade suspended on his M1951 body armor vest, which is fitted with web grenade suspension loops on the left chest. Owing to its oval shape the M26 became known as the “lemon grenade.” OD with yellow markings, this 16oz grenade used the M204A1 fuse as on late examples of the Mk 2A1. It was 3.9in long with a diameter of 2.5in. (US Army)
The Mk IIA1 hand grenade,1 introduced in 1942, was filled with EC blank fire powder. It had no bottom filler hole. In 1944, 1.85oz of TNT replaced the EC powder and M204-series silent-type fuses were fitted. The earlier fuses made a faint pop when ignited and smoked to alert the enemy. The Mk II and Mk IIA1 both weighed 21oz (slight variations depending on the filler) with an overall length of 4.5in (3.5in for the body) and a diameter of 2.3in. On April 2, 1945, the Mk II and Mk IIA1 were redesignated the Mk 2 and Mk 2A1, respectively. They remained in use during the Korean War, including with UN forces, and on into Vietnam. The Mk 2A1 was copied by the Netherlands after World War II and copies were produced by Chile and Taiwan into the 1990s. The flaws of the Mk 2 were long recognized – poor and irregular fragmentation and less blast and fragmentation from the ends, resulting in an inadequate casualty radius. The US Army tested a small number of improved grenades during the war. Reasoning that any red-blooded American boy could throw a baseball with some accuracy, baseball-sized grenades were developed. The 5.5oz T12 and 11.9oz T13 “Beano” fragmentation grenades were impact-detonated. Field testing resulted in accidents and troops rejected them.
Development of the M26 hand grenade began after World War II. To increase lethal fragmentation and provide an evenly dispersed fragmentation pattern, the T38 was developed. It had a sheet-steel, oval body lined with coiled steel wire. The 0.13in-diameter wire was scored every 0.20in ensuring effective uniform fragmentation into 1,150 fragments – each weighing 0.13 grains – to inflict fatal or disabling wounds within 15m (16yd). Killing radius was 5m (5.5yd). The filler hole cap on the bottom contained a layer of pre-scored fragments. The T38 was standardized as the M26 in 1952 and was first used in small numbers in Korea during the spring of 1953. A further improvement was the M26A1, with 0.13in-square wire scored every 0.13in; this was used in all subsequent models. The M26A1 was filled with 5.5oz of Comp B and a 0.25oz tetryl booster.
The M26A2 was an impact-detonated grenade fitted with an M217 impact fuse. This fuse was larger in diameter than the M204. When thrown, the lever flew off and the striker ignited a primer which activated a thermal power source after 1–2 seconds. It would detonate upon impact after that. If it did not impact or the impact mechanism failed, the thermal source continued to burn and would detonate after 4 seconds. If it still failed to detonate, the power source continued to burn for 30 seconds and then became inactive. The lever on early grenades was red with or without “IMPACT” in black. Later grenades had only “IMPACT” embossed on their levers. The troops rejected impact-detonated grenades, however. If after arming they were dropped or struck vegetation they caused friendly casualties. To confuse matters, there was also a non-impact-detonated version of the M26A2 grenade with an M204A1 delay (non-impact) fuse and the small fuse well.
1. Arming pin
2. Arming lever
3. Cast-iron case
4. Mk V primer
5. “Mousetrap” striker
6. 4–5-second delay fuse
7. No. 8 detonator
8. Flaked or granulated TNT filler
9. Filling-hole plug
1. Safety clip
2. Arming lever
3. Cast-iron body
4. Primer
5. Arming pin
6. ‘Mousetrap’ striker and spring
7. 4–5-second delay element
8. Composition 4 filler
9. Detonator
10. Pre-segmented inner surface
The Mk II used several models of fuse over time. They were of the same basic “mousetrap” design. The differences were modifications for improved manufacture, safety, and reliability. All were 4–5-second delay except the M6A4C (4 seconds) and the M10A3 (4.3–5.5 seconds). The M10A1 of 1942 was withdrawn, as the primer flash sometimes bypassed the fuse, causing instantaneous detonation. The M204 series of 1944 had a silent-igniting, non-sparking, non-smoking primer and delay element. The M204A1 was introduced in 1945. Because there were so many grenades in the supply pipeline with older fuses, few of the improved fuses saw combat.
Since 2000, Canada has produced the M67 as the C13 to replace the US M26 series. It suffered high dud rates – 20 in 1,000 as opposed to the US one in 1,000. A licensed copy of the M67 is produced in Switzerland as the HG85 – not to be confused with the Austrian Arges HG85. License-produced M67s have slightly different fuses and safety clips. The M67 and HG85 are used by other European, Middle East, and Far East countries, and most Central American countries. Korea uses the M67 and the domestically produced K400 with a slightly different body shape. It is also popular with Mexican drug cartels and Central American insurgents.
In the mid-1960s a minor modification was added to M26-series grenades to improve safety. Grenades were often hung on suspenders and belts. Grenade rings could catch on vegetation and a pin could be pulled. There were occasional instances of suicidal prisoners lunging at captors, pulling a grenade ring on the soldier, and hugging him to prevent him throwing the armed grenade clear. A wire safety clip, known as the “jungle clip” as it was spawned by events in Vietnam, was fitted to new-production grenades. The advent of the “jungle clip” led to a number of redesignations. The M56 was formally an M26A2 with an M215 fuse – a larger-diameter pyrotechnic delay fuse rather than the usual time fuse – and the safety clip. The M56 was later declared obsolete. The impact-detonated version of the M26A2 was redesignated the M57 with the safety clip added. With the safety clip added, the M26A1 was designated the M61. The M26-series grenades were effective, but offered an inconsistent casualty radius and were heavy, at 1lb. The M26 series began to be replaced in 1968 and production ceased, but it continued in US use into the 1970s.
Development of the M33 hand grenade began in the late 1950s, resulting in a 2.5in-diameter spherical grenade 3.2in high with fuse. It weighed 14oz – 2oz lighter than the M26 – and contained 6.5oz of Comp B, 1oz more than the M26. The 0.13in-thick steel sphere was internally pimpled with a 0.19in segmentation pattern. It breaks up into irregular shaped pieces of 2–12 or more “pimples.” Its lethal radius is 5m (5.5yd), but can cause casualties up to 15m (16yd), dispersing stray fragments up to 230m (250yd). The fragmentation radius was relatively consistent regardless of how the grenade was oriented after landing. The M213 fuse had a 4–5-second delay similar to the M204 series, but a larger detonator negating the need for a booster charge.
A more widely used version, differing from the M33 only by the addition of a safety clip, was the M67 “baseball grenade.” 3.53in long and 2.52in in diameter, it was not fielded until 1968 in Vietnam and while the M26A1/M61 remained in use, by 1969/70, the M67 was more widely employed. A second model was the M33A1, an impact-detonated grenade with an M217 fuse. “IMPACT” was embossed on the lever. It was designated the M59 with the safety clip. The M68 was the same with slight specification changes. Like the M26A2/M57, it was disliked by the troops and fell from use. The M67 remained the standard frag grenade after Vietnam and is still in use. Production ceased in the late 1990s and M67 war stocks were projected to be expended by 2001. With the US involvement in Afghanistan and Iraq, production was resumed, but a new grenade was considered. The Belgian MECAR FRAG-C M72 controlled-fragmentation grenade plus the German Diehl and Austrian Arges lightweight grenades – also controlled fragmentation – were considered. It was determined these grenades were not so superior to the M67 to warrant further testing and converting production lines. Additionally, numerous countries were purchasing M67s from the US or license-producing them so it was becoming practically a NATO standard.
RUAG Ammotec’s HG 85 grenade. The HG 85 is used by Britain as the L109/L109A1 and the Netherlands as the Nr330 and Nr330C1/C2. Instead of the normal straight lever, the HG 85-based grenades have a spoon-shaped lever, preventing it from slipping through another grenade’s arming ring and inadvertently pulling it. The United States did not adopt this spoon-shaped lever as no similar incidents were reported. The L109 and Nr330C1/C2 have plastic safety clips. (CC-BY-SA-2.0-fr/Rama)
The smallest grenade ever fielded was the Dutch-made V40 fragmentation hand grenade, produced by Nederlandse Wape en Munitiefabriek (NWM). Called “mini-frags” or “hooch poppers,” they were issued to US MACV-SOG reconnaissance teams and SEALs in Vietnam from early 1969. The mini-frags were ideal for small reconnaissance teams needing to break contact with superior enemy forces as a large number could be carried. They could be thrown a considerable distance compared to standard grenades. No US designation was assigned, these being special procurement. Canada used the V40 from the late 1970s to 2006. It was withdrawn because the small lever could inadvertently be released when wearing gloves and the activation of the striker not felt.
The runner up is the Yugoslavian Mod. 17 defensive hand grenade (Obrambena Bomba Rucna Mod. 17). This unusually small – for World War II – lemon-shaped grenade was 81mm (3.19in) high (with fuse) and 49mm (1.93in) in diameter.
The spherical V40 grenade was 40mm (1.57in) in diameter, smaller than a golf ball, and the arming-pin ring was almost as large in diameter as the grenade. It was 65mm (2.56in) high with fuse, and weighed 136g (4.80oz). It had 326 internal pre-scored fragments and a 4-second delay. The casualty radius was 18m (20yd). (Paul Bishop)
The Russians developed an all-metal stick grenade in 1914, the RG-14 (Ruchnaya Granata-14, or “hand grenade 1914”). A retaining ring held the handle-mounted arming lever in-place. To arm it, the lever was held down and the safety ring removed. When thrown the lever flew open, releasing a spring-loaded firing pin that ignited the 3.5–5-second delay train. The detonator was inserted into the top of the head. A fragmentation sleeve was available. It was upgraded in 1930 with an improved arming system, as the RG-14/30. It saw limited use at the beginning of World War II, but was quickly replaced by other models. They were sometimes fastened together in bundles of four to attack bunkers and tank treads. The 680g (1.50lb) grenade was 236mm (9.29in) long and 46mm (1.81in) in diameter.
A Russian soldier of World War I with a display of grenades beside his Japanese 6.5mm Type 38 (1905) rifle. Those on the table are French models – the segmented F1 defensive and the egg-shaped M1916 offensive grenades. He holds an RG-14, a blast stick grenade. (Nik Cornish at www.stavka.org.uk)
The Soviet Union expended massive numbers of grenades in the Great Patriotic War of 1941–45, developing numerous models during that conflict. Many remained in use by the Warsaw Pact and client states into the 1990s. Soviet and Russian grenades are olive brown with black markings. The F-1 high-explosive hand grenade (F-1 fugasnyy ruchnaya granata) was a first cousin of the French F1, discussed previously. Nicknamed the Limonka (lemon-like), it was copied from the French F1 grenade in the late 1920s and fielded in about 1930. It could be fitted with two types of fuse, both of which functioned in the same way despite being of a slightly different design. Early grenades were fitted with the Koveshnikov fuse, with a 3.5–4.5-second delay (the East Germans called the F-1 the Koweschnikow). Later grenades used the UZRG, with a 3.2–4-second delay. The Soviet F-1 was made in two variants with different dimensions. The F-1 uses the UZRG or UZRGM lever-delay fuse with a 3.2–4.2-second delay, the standard delay time for most Soviet grenades. 40mm (1.57in) tall, the tubular fuse housing contains a spring-loaded firing pin. The early version was 120mm (4.72in) long with fuse and 65mm (2.56in) in diameter, weighing 700g (1.54lb) and filled with 46g (1.62oz) of TNT. The later version, issued from about 1941 onwards, was 124mm (4.88in) long, 55mm (2.17in) in diameter, and weighed 650g (1.43lb). The filler was 55g (1.94oz) of TNT. Casualty radius was about 20m (22yd).
Most grenades are simple to operate, which is a good thing when you give a hand-launched HE weapon to an infantryman. The pre-World War II Red Army of Workers and Peasants developed the RGD-33 Dyakonov hand grenade (Ruchnaya Granata Dyakonova-33). To employ the RGD-33, the safety switch on the upper end of the handle slid to the left revealing the red “armed” marker. The telescoping outer handle was pulled back, rotated to the right, and the handle released to cock the firing mechanism; the safety switch was slid to the right, exposing the green marker, and was now on safe. The small pivoting cover on the head’s top was opened, the detonator was inserted, and the cover closed. When the user was ready to throw the grenade, the safety switch was slid left, exposing the red marker. When the grenade was thrown, the outer handle was forced back, arming the grenade to detonate in 3.2–3.8 seconds. All that and it required two hands to operate. This was a lot to ask of an under-educated peasant soldier during the stress of combat. Its complexity, along with its cost and production time, resulted in its falling from use early in the Great Patriotic War, although it remained in use with the naval infantry. At least an enemy soldier untrained on the procedure might have difficulty using captured grenades. The Germans, by the way, did use captured RGD-33s, but they had to be trained on them first.
The RGD-33, an all-metal stick grenade, had an internal scored sheet-steel liner coiled four times, and it was provided with a segmented add-on fragmentation sleeve. It was 175mm (6.89in) long and 61mm (2.40in) in diameter with the fragmentation sleeve. (US Army)
Three grenades of the many types used by Finland in the 1939–40 Winter War: (left) Soviet RGD-33 with fragmentation collar; (upper right) Soviet F-1 with UZRG fuse removed; and (lower right) British No. 36M Mk II. Besides wide use in World War II, the F-1 was used in the Spanish Civil War and copied by Spain. It was manufactured by most Warsaw Pact states and remained in use even though more modern Soviet grenades were available. There are variations in production details between countries. Poland adapted the F-1 body to its postwar F-1/N-60 rifle grenade and produced the F-1 until the late 1990s. After World War II, Turkey produced the MKEK Mk 2 grenade using the copied F-1 body with a US-designed M204A2 fuse. The Yugoslavian M15 and M35 defensive hand grenades (obramben bomba rucna M15 i M35) were almost identical to the Russian F-1, but the 5.6-second friction igniters were of a different design. (Tom Laemlein/Armor Plate Press)
The short-lived RG-41 (Ruchnaya Granata-41) had a smooth liner and more complex fuse than its successor, the RG-42 (Ruchnaya Granata-42), adopted in 1942. The fragmentation liner was a thin sheet of steel rolled into three layers with diamond-pattern segmentations. The RG-42 used the same UZRG lever-delay fuse as the F-1. These grenades required no casting and were produced in existing can-making plants. 121mm (4.76in) long and 54mm (2.13in) in diameter, they remained in use within the Warsaw Pact and Communist China (as the Type 42) after the Great Patriotic War.
The RGD-5 distance hand grenade (Ruchnaya Granata Distantsionnaya 5) was introduced in 1954. Produced in several Warsaw Pact countries and China (as the Type 59), it is found the world over. An RGD-5 was thrown at US President George W. Bush and the president of Georgia in 2005, but failed to detonate. Introduced in the mid-1980s, the RGN (Ruchnaya Granata Nastupatel’naya) and RGO (Ruchnaya Granata Oboronitel’naya) are blast and fragmentation grenades, respectively. They are widely distributed today, being produced in Russia and the Ukraine.
The RGN (left) and RGO (right) hand grenades measure 114mm (4.49in) tall and 60mm (2.36in) in diameter. The RGN has a smooth, spherical body internally scored to generate short-ranged aluminum fragments and has a casualty radius of 4–10m (4–11yd). The RGO has a two-layer pre-fragmented steel body and a casualty radius of 6–20m (6.5–22yd). The white plastic UDZS impact fuse arms after 1–1.8 seconds to detonate on impact, or after 3.2–4.2 seconds. The bodies are olive drab and the plastic fuse housings are white. (US Army)
The Soviet UZRGM lever-delay fuse (Unifitsirovannyy Zapal Ruchnaya Granaty Modernizirovaiiyy, or “universal-fitting hand grenade fuse, modernized”) was used in the F-1, RG-42, and RGD-5. The delay is 3.2–4.2 seconds. In 1983, an American “action adventure” magazine published an article stating the UZRGM was provided with varied time delays ranging from 0 to 13 seconds at 1-second intervals. This misbegotten theory was based on a small stamped number on the fuse body concealed inside the grenade when inserted. This is not true. It fails to explain the actual 3.2–4.2-second standard delay for one thing, nor is there an external warning identification of “short” or “long” delays when inserted in grenades. It is absurd to think that there would be no form of warning on fuses set to detonate in less than 3 seconds. Additionally, they were randomly mixed in fuse-packing cans without any warning markings. While a zero-delay fuse is valuable for booby-trapping, it is hard to see what the value of 1- and 2-second delay fuses could be, much less any practical use of grenades with 6–13-second delays. All UZRGM fuses have the same 3.2–4.2-second delay regardless of the stamped number. The number indicates only the factory production line. This myth actually found its way into the US Army’s 1988 FM 23-30, Grenades and Pyrotechnic Signals, and was not deleted until the 2000 edition.
Grenades used by Communist Chinese and North Korean forces during the 1950–53 Korean War (left to right): Type 42 (Soviet RG-42), two different types of Chinese-made stick grenades, and a Type 1 (Soviet F-1). Communist China produced the F-1 as the Type 1 hand grenade as well as stick-grenade versions fitted to the fuse well containing a friction igniter. F-1s and Chinese Type 1s also saw use in Vietnam and various African conflicts. The stick grenade on its end was copied by the Japanese as the Type 98 (1938). The fountain pen for scale is about 140mm (5.5in) long. (Tom Laemlein/Armor Plate Press)
During the Russo-Japanese War the Japanese made wide use of expedient grenades little different from later British trench-made grenades. In addition to pipe bombs – dynamite-filled with a mining safety fuse and blasting cap – they filled 37mm and 47mm gun cartridges with gun-cotton charges. One of the first models of purpose-made Japanese grenades was a multipurpose munition – the Taisho Type 10 (1921) hand and discharger grenade. This HE grenade could be thrown as a hand grenade with a 4–5-second percussion delay fuse, or fired from the 5cm Taisho Type 10 (1921) or the later Type 89 (1929) grenade dischargers. A propellant charge and primer assembly could be screwed into the base well for the latter role. Weighing 565g (1.25lb), 110mm (4.33in) long, and 50mm (1.97in) in diameter, the Type 10 was replaced by the Type 91, but remained in limited use into the 1940s.
Japanese hand grenades: (left to right) Type 98 (1938) stick grenade copied from a Chinese model and produced in Manchuria; Type 97 (1937) hand grenade with zero-delay fuse for booby-trapping, identified by the white bottom; Type 91 (1931) hand and discharger grenade with “knee mortar” propellant charge attached; Type 97 (1937) hand grenade with standard 4.5-second delay; and Type 99 (1939) hand and rifle grenade, the “Kiska grenade.” These grenades were painted black and had brass covers on the percussion fuses. The tops were painted red to signify they had an explosive filler (except for the stick grenade). (Tom Laemlein/Armor Plate Press)
1. Arming pin
2. Arming lever
3. Steel body
4. Firing pin and spring
5. Primer
6. 3.2–4.2-second delay element
7. TNT filler
8. Detonator
9. Fragmentation liner
1. Two-prong arming pin
2. Protective cap
3. Cast-iron body
4. Grenade-discharger propellant charge
5. Firing pin, spring, and holder
6. Primer
7. Top filler plug
8. 7–8-second delay fuse
9. Igniter charge
10. Flaked TNT filler
11. Booster charge
12. Grenade-discharger propellant charge smokeless-powder filler
13. Grenade-discharger propellant charge primer
Oval-shaped, the Soviet RGD-5 hand grenade is 117mm (4.61in) long and 58mm (2.28in) in diameter. Featuring a pre-scored fragmentation liner (300 fragments) and using the UZRGM lever-delay fuse, it is often assumed to be a blast grenade owing to its two-piece smooth body.
As a rifle grenade, the Japanese Type 91 grenade had a tailboom assembly screwed into the base. As a grenade discharger round, the grenade had a propellant charge screwed into the base. A two-pronged arming fork was pulled to arm the igniter before striking it on a solid object. When it was used as a mortar round or rifle grenade, the percussion igniter was not struck, but the pin pulled and dropped down the mortar tube or placed on the launcher. The recoil activated the firing pin to ignite the 7–8-second delay. The Type 91 was extremely unreliable, with frequent duds. Fragmentation was poor, with reports of grenades breaking into as few as two pieces. Others reported “dust-like” fragments.
Marine Raiders on Guadalcanal unscrew the fuses of small Japanese Type 97 (1937) grenades. They will pop the percussion caps after removing the detonators and delay fuse and then carefully scrape out the 2oz TNT filler. The demilitarized grenades would then be passed out as souvenirs. (Tom Laemlein/Armor Plate Press)
During World War II Japanese hand grenades – kuichi shiki shuryūdan (preceded by type number) – were of marginal quality, with light blast and fragmentation. It was recommended to Americans using them to throw such grenades immediately after activating them, owing to the possibility of short fusing. These grenades had percussion-type fuses initiated by striking the percussion cap on a solid object after pulling the safety pin. They were identified by black bodies and red tops, indicating an HE filler. The Type 91 (1931) hand and discharger grenade was a multipurpose grenade that could be thrown as a hand grenade, fired from a spigot-type rifle grenade launcher, or fired from the 5cm Type 89 (1929) grenade discharger (“knee mortar”). The Type 97 (1937) hand grenade was a Type 91 without the “knee mortar” propellant charge well. Cylindrical with a segmented body, both were 95mm (3.74in) long – or 126mm (4.96in) with charge – and 50mm (1.97in) in diameter.
The Type 98 (1938) stick grenade had a screw-on cap on its hollow wooden handle, protecting a pull-cord and friction igniter. 179mm (7.05in) long and 50mm (1.97in) in diameter, it had a cast-iron head 6mm (0.24in) thick and providing poor fragmentation. It was copied from a Chinese model (which was also used by the Japanese) and produced in Manchuria by the Japanese. The Type 99 (1939) hand and rifle grenade possessed an improved percussion igniter, as the Type 91 and Type 97 functioned poorly in North China’s cold. The Type 99 had a non-segmented iron body providing limited fragmentation relying mainly on blast, which was limited using picric acid with a Trotyl booster. It could be fired from the Type 100 (1941) cup-type rifle grenade launcher. It was called the “Kiska grenade” by US forces as it was first encountered by them on Kiska Island in the Aleutians in 1943.
1 Some references state the Mk IIA1 designation was not official and only used by collectors to identify later Mk IIs without filler holes. The Mk IIA1 is identified as such in Army technical manuals.