The K-tool is a tool use by many fire departments for forcible entry. It is used in conjunction with a Halligan bar and a flat-headed axe or maul (commonly referred to as "irons" or (with a maul instead of an axe) "strong irons") to remove a cylinder lock. It consists of a steel block roughly 3 inches by 3 inches by 1 inch thick with a K-shaped notch on one side, having sharp edges that grip the cylinder, and a U-shaped flange on the other side. The notch is slipped over the lock cylinder, then forced down by striking with the flat side of the axe or maul. The halligan is then inserted into the flange and used to pry the K-tool off the door, thereby pulling the entire key cylinder out. The bolt is then retracted from the inside of the cylinder hole using a turning tool, such as a screwdriver.