Rigid Shaft Coupling Bore Diameter 1 2 1/4 in Bore Diameter 2 2 1/4 in Bore Type Round Clearance Diameter 3.5 in Coupling Construction One-Piece Coupling Material Carbon Steel Coupling Outside Diameter 3 1/2 in Different Bore Sizes No Keyway Depth 1 Not Applicable Keyway Depth 2 Not Applicable Minimum Bore Diameter 2 1/4 in Keyway Width 1 Not Applicable Keyway Width 2 Not Applicable Maximum Bore Diameter 2 1/4 in Maximum Speed 4 000 RPM Maximum Torque 13 680 in-lb