Shaft Collar System of Measurement Inch Bore Type Round Keyed Bore Diameter 3/4 in Bore Thread Size Not Applicable 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 3/16 in Collar Material Grade 1215 Keyway Depth 3/32 in Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 2-Piece Screw Material Alloy Steel