Malco No. 7 Sizes X 1/2 in. L Slotted Hex Washer Head Sheet Metal Screws 100 pk

Malco Products, SBC got its start in 1950 when a young steel supply salesman, Mark W. Keymer, decided to manufacture and market a pipe crimper he had invented for use in installing the “new�?sheet metal ductwork used with forced air heating systems. More tools soon followed, including the first hand seamer to employ compound leverage, a time saving hand notcher that made a V-shaped cut in one motion and a hand operated, snap lock punch to complete the basic sheet metal tool set.