split pin

split pin (plural split pins)

1. A metal fastener with two tines, the ends of which project through an object being fastened and are bent back to hold it in place.
2. A stationery fastener that is inserted into punched holes in a stack of paper before being bent to secure them.

• (metal fastener): cotter pin (US), cotter key (US)
• (stationery fastener): brad, brass fastener, butterfly clip, paper fastener

• rivet
• staple