Used to lock castle or hex slotted nuts in place. 1/4" Zinc plated cotter pins are inserted into a hole that has been drilled through a bolt after the nut has been installed. The cotter, or split pin is then deformed with a pair of pliers to prevent it from comming back out of the hole. This in turn prevents the nut from being able to vibrate. Pins, Cotters, Rings. Pivot Point has diverse manufacturing capabilities that include cold heading, screw machining, high-speed drilling, CNC/Swiss-turning, ball detenting, milling, bending, secondary operations and more. Cold headed parts are available with a variety of head styles available including standard IFI heads, button heads, truss.