Acme Threaded Shaft Collar, System of Measurement Inch, Bore Type Threaded, Bore Diameter 3/4 in, Bore Thread Size 3/4 In.-6, 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 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 1-Piece, Screw Material Alloy Steel