Shaft Collar System of Measurement Metric Bore Type Round Bore Diameter 18 mm Bore Thread Size Not Applicable Collar Outside Diameter 36 mm Inside Height to Flat Not Applicable Clearance Diameter 41.1 mm Collar Width 13 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