Keyless Bushing Flange Type Not Applicable For Bore Diameter 3/8 in Keyless Bushing Type Single Nut Locking Assembly Material Steel Outside Diameter 3/4 in Overall Width 0.875 in System of Measurement Inch Finish Oil Dipped Hub Contact Pressure 18 147 psi Maximum Transmitted Torque 421 ft-lb Outside Diameter Tolerance +/-0.0015