Shaft Collar System of Measurement Metric Bore Type Round Bore Diameter 6 mm Bore Thread Size Not Applicable Collar Outside Diameter 16 mm Inside Height to Flat Not Applicable Clearance Diameter 20.8 mm Collar Width 19.6 mm Collar Material Carbon Steel Keyway Width Not Applicable Collar Material Grade 1215 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 2-Piece Screw Material Alloy Steel