Shaft Collar System of Measurement Inch Bore Type Round Bore Diameter 2 5/8 in Bore Thread Size Not Applicable Collar Outside Diameter 3 7/8 in Inside Height to Flat Not Applicable Clearance Diameter 4.15 in Collar Width 7/8 in Collar Material Carbon Steel Keyway Width Not Applicable Collar Material Grade 1215 Keyway Depth Not Applicable Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 2-Piece Screw Material Alloy Steel