Shaft Collar System of Measurement Metric Bore Type Round Bore Diameter 5 mm Bore Thread Size Not Applicable Collar Outside Diameter 16 mm Inside Height to Flat Not Applicable Clearance Diameter 20.8 mm Collar Width 9 mm Collar Material Plastic Keyway Width Not Applicable Collar Material Grade Acetal Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 1-Piece Screw Material Stainless Steel