Gcres, ams5630, 40 min, 55 max rockwell c scale hardness, 0.765 in. Min, 0.775 in. Max o/a w, 1.125 in. C to c distance between link and shaft holes, 0.765 in. Min, 0.775 in. Max shaft end thk, 0.240 in. Min, 0.250 in. Max link end thk, 0.500 in. Distance from shaft hole center to end, 0.450 in. C to c offset distance between shaft and link end holes, 0.3115 in. Min, 0.3135 in. Max diameter shaft end hole, 0.1600 in. Min, 0.1662 in. Max link end hole dia, thd, 0.190-32-nf-3b