Mushroom and Spool Pin Tumbler Locks

High-security pin tumbler locks may contain specially made pins to make picking them more challenging. The pins are machined so as to make picking them quite difficult. When picking these locks, the pins give the impression that they have broken, when in fact they could be a long way from breaking. You can tell whether or not you are picking a pin tumbler lock that has these pins by the fact that the pins seem to align so easily with a louder than normal click. The cylinder seems eager to open but to no avail.

Figure 27. The spool pin is at left, and the mushroom pin is at right.

The picking procedure relies on a well-yielding tension wrench. The tension wrench has to be lightly spring-loaded so that the pins can bypass their false breaking points. You also have to “rake” (seesaw in and out) the pins with your pick. The feather-touch tension wrench is ideal for the job. Use light pressure with it, and it will let you in.

The mushroom and spool pins are used in locks for high-security purposes such as bank doors. The American Lock Company uses them in some of their padlocks.