Shaft Collar System of Measurement Metric Bore Type Round Bore Diameter 6 mm Bore Thread Size Not Applicable Collar Outside Diameter 3/4 in Inside Height to Flat Not Applicable Clearance Diameter 28.81 mm Collar Width 9 mm Collar Material Carbon Steel Keyway Width Not Applicable Collar Material Grade 1211 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 1-Piece Screw Material Carbon Steel