Shaft Collar System of Measurement Metric Bore Type Round Bore Diameter 3 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 Stainless Steel Keyway Width Not Applicable Collar Material Grade 303 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 1-Piece Screw Material Stainless Steel