1/8 x 2 1/2 Cotter Pin Zinc Plated . These cotter pins consist of a double bodied pin formed from half-round wire, a loop at one end of which provides a head. The finished part has one end of the wire extending beyond the other end, with a chiseled point. Cotter pins are used to anchor various assemblies by insertion into a drilled hole of a shaft or pin and spreading the points to hold the assembly in position. When used with castle or slotted nuts, it becomes a safety locking device. Manufactured from 1005 - 1010 low carbon steel, each prong of the cotter pin will be capable of withstanding being bent back upon itself once with no visible indication of fracture occurring at the point of the bend.