Shaft Collar System of Measurement Inch Bore Type Round Keyed Bore Diameter 3/8 in Bore Thread Size Not Applicable Collar Outside Diameter 7/8 in Inside Height to Flat Not Applicable Clearance Diameter 1.03 in Collar Width 11/32 in Collar Material Aluminum Keyway Width 3/32 in Collar Material Grade 2024 Keyway Depth 3/64 in Thread Direction Not Applicable Center to Lever Top Not Applicable Collar Construction 2-Piece Screw Material Alloy Steel Screw Material Finish Black Oxide