Spring plunger

Typically, it is a machine part consisting of a hollow cylinder with an internal compression spring acting on a pin.

Alternatively, it can be made directly into the workpiece by drilling and tapping a hole, then inserting a pin (or ball), spring, and finally a set screw.

Different plungers may require different tools for installation, such as a hex key, socket wrench, or flathead screwdriver.

Some spring plungers are designed to be handled only when assembling or occasionally adjusting equipment.

A pogo pin is a type of electrical connector mechanism widely used in modern electronics.