L.S. STARRETT 75A-3 FAY SPRING TYPE OUTSIDE CALIPER SOLID NUT 3" SIZE Starrett calipers are exceptionally rugged in construction. The legs are made from heavy square stock and machined to a smooth taper. The fulcrum stud is hardened and has an exceptionally large bearing surface to prevent side deflection of the legs. The bow spring is both strong and flexible, and the adjustment screw is centrally located in the legs to assure smooth action.