Toggle mechanisms are used to obtain large force amplification in such applications as sheet metal punching and forming machines.

This bench top apparatus can be used to investigate forces exerted within a toggle mechanism. Load is applied to the two pairs of links by a hanger suspended from their connecting pivot. One end of the links is pivoted to a base, and the other end is free to move sideways on ball bearing wheels. The moving links are held by a horizontal spring balance, which measures the horizontal reaction directly. The angle of the toggle can be varied. There are many ways in which the forces can be determined theoretically.