Shaft Collar, System of Measurement Inch, Shaft Locking Type - Couplings 1 Piece Clamp, Bore Type - Collars Plain Bore, Bore Dia. 3 in, Material - Collars Black Oxide Steel, Outside Dia. 4 1/4 in, Width 7/8 in, Clearance Dia. 4.562 in, Screw Size 3/8 In. -24, Screw Material Steel, Operating Temp. Range 0 Degrees to 300 Degrees F