Shaft Collar System of Measurement Inch Bore Type Threaded Bore Diameter 1 1/2 in Bore Thread Size 1 1/2 In.-6 Collar Outside Diameter 2 3/8 in Inside Height to Flat Not Applicable Clearance Diameter 2.58 in Collar Width 9/16 in Collar Material Carbon Steel Keyway Width Not Applicable Collar Material Grade 1215 Keyway Depth Not Applicable Thread Direction Right Hand Thread Center to Lever Top Not Applicable Collar Construction 1-Piece Screw Material Alloy Steel