These hand retractable plungers have a wide range of applications to lock items in place. They are used for positioning, locating and fastening, without the use of tools, in a wide range of applications. As the handle is turned 180 degrees on the cam of the body, the plunger is retracted into the housing. The housing of the plunger is designed to be welded into place for strength. There is a groove on the top of the cam that locks the plunger into the retracted position. The plunger pin, handle and housing are made from AISI-4140 alloy steel with a black oxide finish. The spring is made from 17-7 stainless steel.