Shaft Collar, System of Measurement Inch, Bore Type Threaded, Bore Diameter 5/16 in, Bore Thread Size 5/16 In.-18, Collar Outside Diameter 11/16 in, Inside Height to Flat Not Applicable, Clearance Diameter 0.84 in, Collar Width 9/32 in, Collar Material Carbon Steel, Keyway Width Not Applicable, Collar Material Grade 1215, Keyway Depth Not Applicable, Thread Direction Right Hand Thread, Center to Lever Top Not Applicable, Collar Construction 1-Piece, Screw Material Alloy Steel This product contains a chemical that is regulated under California Proposition 65. Warning: This product contains a chemical known to the State of California to cause cancer. Warning: This product contains a chemical known to the State of California to cause birth defects or other reproductive harm. -