Shaft Collar, System of Measurement Inch, Shaft Locking Type - Couplings 2 Piece Clamp with Keyway, Bore Type - Collars Plain Bore, Bore Dia. 1 3/4 in, Material - Collars Black Oxide 1215 Lead Free Steel, Outside Dia. 2 3/4 in, Width 11/16 in, Clearance Dia. 3.046 in, Screw Size 5/16 In. -24, Screw Material Alloy Steel, Operating Temp. Range -40 Degrees to 350 Degrees F