A comb pick is a lockpicking tool designed to pick pin-tumbler locks by moving all pin stacks completely above the shear line, leaving no obstructions to prevent rotation of the plug. Comb picks may either compress springs or forcibly remove poorly fastened chamber casings to allow springs and pins to be moved further.
Balanced pin stacks are used to prevent this technique. In addition, the use of screwed or riveted chamber casings prevent forced removal of the chamber casing.
One of the earliest references to comb picks is from Francis Buday's 1934 patent entitled "MEANS FOR UNLOCKING LOCKS". In the patent he describes the use of a comb pick with a key blank to assist raising the tool to the shear line:
- The method of the invention consists in first inserting and auxilliary key element designed to retain in upward or unengaging position the series of plungers out of contact with the rotatable cylinder (14), and then to insert the main turning key adapated in association with the auxilliary key portion to be introduced into the aperture of the lock and to turn said lock portion together with the lock spindle.
- Buday, Francis. 1934. "MEANS FOR UNLOCKING LOCKS". US 2,064,818