Jaw Coupling Hub Coupling Size JC12 Outside Diameter 3/4 in Coupling Overall Length 1 1/16 in System of Measurement Inch Hub Material Aluminum Maximum Speed 8 000 RPM Keyway Depth Not Applicable Keyway Width Not Applicable Bore Diameter 5/16 in Shaft Locking Type Clamp On Bore Type Round Bore Jaw Profile Curved Screw Thread Size M2.5 Bore Tolerance +0.002/-0.000 in Fail Safe Yes Shaft Tolerance +0.0000/-0.0005 in Full Bearing Support Required Yes Hub Diameter 3/4 in