magnify force, as in the parrotfish jaw. One interesting application of the four bar linkage is found in locking pliers. The B-C and C-D links are set at an angle close to 180 degrees.
Clamp on a locking pliers for a handle. — Art Lipstraw. Channellock pliers are a great tool for cracking nuts. The jaws adjust easily so you can crack large walnuts or small hazelnuts.