Shaft Collar System of Measurement Inch Bore Type Threaded Bore Diameter 3/4 in Bore Thread Size 3/4 In.-16 Collar Outside Diameter 1 1/2 in Inside Height to Flat Not Applicable Clearance Diameter 1.81 in Collar Width 1/2 in 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