Tire Coupling Hub, Angular Misalignment 4 Degrees , Coupling Size WE4, Horsepower @ 100 RPM 0.88 hp, Maximum Speed 7,500 RPM, Bore Type Round Keyed, For Bushing Size Not Applicable, Maximum Torque 550 in-lb, Keyway Depth 3/32 in, Keyway Width 3/16 in, Hub Diameter 2.6 in, Parallel Misalignment 0.0625 in, Bore Diameter 7/8 in, Screw Thread Size 1/4 In.-20, Set Screw Location Over Keyway, System of Measurement Inch, Torsional Stiffness 5,370 in-lb/rad, Length through Bore 1 11/16 in