Wire forming can be done in a number of ways. Cotter pins are formed similar to cold heading, except that the dies are designed so that the wire is pushed around them and the wire forms around the die.
A fourslide is often used to form bridge pins and other complicated wire forms. The fourslide is wire fed and uses cams and a single motor that are timed to four dies that sit around the outside perimeter of a rotary table. The cams time the die impact into the wire, with the wire formed around the dies, similar to a cotter pin. Each machine stroke advances the part one more station forward progressively. After the fourth impact, the formed part is ejected through a hole in the middle of the rotary table. The opportunity for four impacts allows for rather complicated design capabilities. Fourslides can also design in-line, but are based on the same operating principles.
