METHOD FOR FORMING TAPERED PISTON PINS

摘要

A method is provided for cold forming center web or webless tapered piston pins in one forming sequence. The method eliminates secondary operations such as but not limited to machining, annealing, coating and secondary forming. The method includes the steps of cutting a metal rod into a substantially cylindrical slug piece, die extruding the slug piece to form a first cavity in the slug piece, optionally die extruding the slug piece to form a second cavity in the slug piece, piercing the slug piece to form the slug piece into a hollow cylindrical piece, die extruding the hollow cylindrical piece at either end to form a hollow cylindrical piece having a taper on an internal surface of the hollow cylindrical piece at either end.