Mac-It is one of the leading suppliers of special threaded parts in the United States. For more than 92 years, the company has been manufacturing precision fasteners. It manufactures hex, square, spline and high-torque sockets, as well as slotted, hex, button, flat and square heads with standard or metric threads. Situated in Lancaster, Pa., Mac-It is an ISO 9001:2000 certified company. The company s extensive inventory of screws comprise seat, arbor, hollow lock, clamp, tool post, square head set and endmill screws.