Acme Threaded Shaft Collar, System of Measurement Inch, Bore Type Threaded, Bore Diameter 3/8 in, Bore Thread Size 3/8 In.-12, Collar Outside Diameter 7/8 in, Inside Height to Flat Not Applicable, Clearance Diameter 1.03 in, Collar Width 11/32 in, Collar Material Stainless Steel, Keyway Width Not Applicable, Collar Material Grade 303, Keyway Depth Not Applicable, Thread Direction ACME Thread, Center to Lever Top Not Applicable, Collar Construction 1-Piece, Screw Material Stainless Steel WARNING: This product can expose you to chemicals including Nickel (Metallic), which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov. -