Shaft Collar System of Measurement Inch Bore Type Round Bore Diameter 5/8 in Bore Thread Size Not Applicable Collar Outside Diameter 1 1/8 in Inside Height to Flat Not Applicable Clearance Diameter 1.13 in Collar Width 1/2 in Collar Material Stainless Steel Keyway Width Not Applicable Collar Material Grade 304 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 1-Piece Screw Thread Size 5/16 In.-18