Abstract: A headed pin for use in pin tumbler locks is provided with a release diameter cylindrical body having an enlarged diameter axially short head at one end, the reduced diameter body being received internally of a biasing spring which bottoms against an underside of the head, the spring extending beyond the end of the cylindrical body opposite the head, and the headed pin and spring being received in one or more of the pinholes as the upper pin in a pin tumbler lock.