That part of the lock mechanism containing a square hole to admit the spindle (to which door handles are attached) which pulls back the springbolt when turned.
The part of a wardrobe lock or spring latch that pulls the latch into the body of the lock allowing the door to open. There is a square hole in the follower to allow a spindle attached to a knob or handle to go in. When the knob is turned this turns the follower which opens the latch.
That part in a firearm which, through the action of a spring, forces a cartridge or cartridges to move.
The plate on the top of the spring in a magazine that supports the ammunition and positions the rounds for loading into the chamber.
part of the latch mechanism that contains a square hole, through which the square spindle for the handle sits. Turning the follower moves the latch tongue.
This is a cylindrical object of the same outer diameter as the plug (there are various diameters, often about 1/2") which is used to push out or follow the plug when the plug is to be removed. This retains the top pins and springs in the lock body.