Shaft Collar System of Measurement Inch Bore Type Round Bore Diameter 2 7/8 in Bore Thread Size Not Applicable Collar Outside Diameter 4 3/4 in Inside Height to Flat Not Applicable Clearance Diameter Not Applicable Collar Width 3/4 in Collar Material Aluminum Keyway Width Not Applicable Collar Material Grade 6061 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top 2.38 in Collar Construction 1-Piece Screw Material Stainless Steel