A pintle is a pin or bolt, usually inserted into a gudgeon, which is used as part of a pivot or hinge. In sailing, a pintle is inserted into a gudgeon to hold the rudder onto the boat. In transportation, a pintle hitch/hook is a claw- or pincer-type device that clamps through a lunette ring on the tongue of a trailer. In controllable solid rocket motors it's the plug that's moved into and out of the motor throat to control thrust. In the military, a pintle is used with light machine guns… (More on Pintle)