Extended prong cotter pins are similar to standard cotter pins but are manufactured with longer legs. They are specialty items used for custom manufacturing and repair work because they can be cut to size.

Bridge pins, also called R-clips or hitch pin clips, insert into the ends of hitch or clevis pins to secure them in place. They feature a wave-patterned leg that secures the pin and resists pull-out from vibration and accidental contact.

Hammerlock cotter pins, sometimes called castle keys or castle nut cotters, are inserted into holes in an assembly and secure castle nuts in place against vibration and other loads. They are formed so that when hammered into place their legs expand, locking the pin in position. Unlike other cotter pins, they are not reusable as the installation process permanently deforms their legs and heads.