Shaft Collar System of Measurement Inch Bore Type Round Bore Diameter 5/16 in Bore Thread Size Not Applicable Collar Outside Diameter 11/16 in Inside Height to Flat Not Applicable Clearance Diameter 0.75 in Collar Width 5/16 in Collar Material Carbon Steel Keyway Width Not Applicable Collar Material Grade 1045 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 1-Piece Collar Material Finish Black Oxide