Split Pins: Half-Round Wire Folded, Pinched and Twisted (Britton 1925)

A split pin is one piece of half-round wire folded in two, flat faces together, so the two legs make a round shank with an eye at the top. Britton's machine cuts the wire, folds it round a pin, pinches the legs together so the eye sits to one side, and twists the eye a quarter turn so it lines up with the split. Source: William M. Britton, US 1,536,284 (1925). Unknown: the wire's metal and the sizes. Britton gives neither, so they are linked to unknown heads. Picture: the patent's sheet 1.