Rigid Shaft Coupling, 1 Piece Set Screw, Inch, Bore Dia. 3/4 in, Stainless Steel, Finish Plain, Outside Dia. 2 1/4 in, Overall Length 2 in, With Keyway, Clearance Dia. 1.5 in, Screw Size 5/16 In. -18, Keyway Width 3/16 in, Max. Torque 338 in-lb, Max. RPM 3, 500 RPM