Shaft Collar System of Measurement Metric Bore Type Threaded Bore Diameter 8 mm Bore Thread Size M8x1.25 Collar Outside Diameter 18 mm Inside Height to Flat Not Applicable Clearance Diameter 22.4 mm Collar Width 9 mm Collar Material Stainless Steel Keyway Width Not Applicable Collar Material Grade 303 Keyway Depth Not Applicable Thread Direction Right Hand Thread Center to Lever Top Not Applicable Collar Construction 1-Piece Screw Material Stainless Steel