Shaft Collar, System of Measurement Inch, Bore Type Round, Bore Diameter 5/8 in, Bore Thread Size Not Applicable, Collar Outside Diameter 1 5/16 in, Inside Height to Flat Not Applicable, Clearance Diameter 1.5 in, Collar Width 7/16 in, 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 1-Piece, Screw Material Alloy Steel This 1-pc. clamp-style shaft collar is made to Ruland's exacting standards to help ensure performance benefits, including tightly controlled face-to-bore perpendicularity (TIR Less Than or Equal To 0.002") for proper alignment of mating components. It is machined from bar stock from North American mills selected to help.