Shaft Collar System of Measurement Metric with Inch Bore Bore Type Round Bore Diameter 5/8 in Bore Thread Size Not Applicable Collar Outside Diameter 30 mm Inside Height to Flat Not Applicable Clearance Diameter 32.3 mm Collar Width 8 mm Collar Material Aluminum Keyway Width Not Applicable Collar Material Grade 2024 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 1-Piece Screw Material Alloy Steel