Shaft Collar System of Measurement Inch Bore Type Round Bore Diameter 1 3/8 in Bore Thread Size Not Applicable Collar Outside Diameter 2 15/16 in Inside Height to Flat Not Applicable Clearance Diameter Not Applicable Collar Width 19/32 in Collar Material Aluminum Keyway Width Not Applicable Collar Material Grade 6061 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top 1.47 in Collar Construction 1-Piece Screw Material Stainless Steel