Acme Threaded Shaft Collar, System of Measurement Inch, Bore Type Threaded, Bore Diameter 1/2 in, Bore Thread Size 1/2 In.-10, Collar Outside Diameter 1 1/8 in, Inside Height to Flat Not Applicable, Clearance Diameter 1.28 in, Collar Width 13/32 in, Collar Material Carbon Steel, Keyway Width Not Applicable, Collar Material Grade 1215, Keyway Depth Not Applicable, Thread Direction ACME Thread, Center to Lever Top Not Applicable, Collar Construction 2-Piece, Screw Material Alloy Steel