GLOSSARY

Active gas	A gas, such as oxygen, that will react with other substances.
Alloy	A substance composed of two or more metals or a metal and other non-metal material.
Arc welding	Welding processes that use an electric arc to produce heat to melt and fuse the base metals. Often used to refer specifically to shielded metal arc welding.
Backfire and flashback	Combustion taking place inside the oxyacetylene torch creating a loud pop or explosion.
Base metal	The metal that is being welded, brazed, braze welded, or cut.
Bead or weld bead	The seam between workpieces that have been joined with welding.
Braze	A process used to join metals using a non-ferrous material that melts above 850° F but below the melting point of the base metal. Brazing uses capillary action to join closely fitted parts.
Braze welding	A process used to join metals with a filler material that melts above 840° F and below the melting point of the base metal where the filler metal is not distributed by capillary action.
Butt joint	A joint between two workpieces in the same plane.
Carburizing flame	An oxyfuel flame with an excess of fuel.
Consumable electrode	An electrode that also serves as the filler material.
Corner joint	A joint between workpieces meeting at right angles and forming an L shape.
Cutting tip	Converts an oxyfuel welding torch into an oxyfuel cutting torch.
Direct current electrode negative	Direct current welding where the electrode is negative and the workpiece is positive.
Direct current electrode positive	Direct current welding where the electrode is positive and the workpiece is negative.
Duty cycle	The amount of continuous time in a 10-minute period that an arc welder can run before it needs to cool down. Expressed as a percentage at a given amperage output.
Edge joint	A joint between parallel workpieces.
Electrode	The conductive element that makes the connection with the workpiece to create an electrical arc.
FCAW	Flux cored arc welding.
Filler, filler metal	Metal added to a welded joint.
Fillet weld	A triangular shaped weld between two members that meet at 90° angles.
Flame cutting	See oxyfuel cutting.
Flux	A chemical compound that produces cleaning action and reduces the formation of oxides when heated.
Flux core, flux cored wire	An electrode for flux cored arc welding that contains flux within a wire tube.
Flux cored arc welding (FCAW)	A semi-automatic arc welding process using an electrode wire that contains flux.
Gas metal arc welding (GMAW)	A semi-automatic arc welding process using a wire electrode which also is the filler material. An inert gas is distributed over the weld area to shield the molten metal from oxygen. Commonly referred to as MIG (metal inert gas) or wire feed.
Gas tungsten arc welding (GTAW)	An arc welding process using a tungsten electrode, hand-held filler material, and an inert shielding gas. Also referred to as TIG (tungsten inert gas) and Heliarc.
GMAW	Gas metal arc welding.
Groove weld	A weld made in grooves between workpieces.
GTAW	Gas tungsten arc welding.
Heliarc	Gas tungsten arc welding.
Inert gas	A non-reactive or non-combining gas such as argon or helium.
Kerf	The width of a cut.
Lap joint	A joint between overlapping workpieces.
MIG	Metal inert gas—see gas metal arc welding.
Oxyacetylene cutting	Oxyfuel cutting using acetylene as the fuel gas.
Oxyacetylene welding	Oxyfuel welding using acetylene as the fuel gas.
Oxyfuel cutting	Cutting process using the combustion of a pressurized fuel gas and oxygen to heat steel to 1600° F at which time a pure oxygen stream is delivered to burn through the metal. Also called flame cutting.
Oxyfuel welding	Welding process that uses the heat produced by the combustion of a pressurized fuel gas and pressurized oxygen. A hand-held filler material is used. Also called gas welding.
Plasma cutting	An arc cutting process using a constricted arc. Compressed air or inert gas blows the molten metal from the kerf
Plate	Flat metal thicker than 3/16".
Saddle joint	A joint between round tubes where one tube has been cut to fit around the other.
Sheet metal	Flat metal 3/16" or less in thickness.
Shielded metal arc welding (SMAW)	An arc welding process using a flux coated consumable electrode. Also referred to as arc welding or stick welding.
Shielding gas	A gas that prevents contaminants from entering the molten weld pool.
Slag	Oxidized impurities formed as a coating over the weld bead; waste material found along the bottom edge of an oxyfuel cut.
SMAW	Shielded metal arc welding.
Spatter	Small droplets or balls of metal stuck to the base metal around the weld. Produced by shielded metal arc, gas metal arc, and flux cored arc welding.
Stick welding	Shielded metal arc welding.
T-joint	A joint between workpieces meeting at right angles and forming a T shape.
TIG	Tungsten inert gas—see gas tungsten arc welding.
Wire feed	See gas metal arc welding.