Zinc Plated Steel Shaft Collar, Set Screw Collar Style, Standard Dimension Type, 1 in Bore Dia./ OUTSIDE DIAMETER: 1.500 INCHES NOMINAL THICKNESS: 0.562 INCHES NOMINAL BORE DIAMETER: 1.0000 INCHES NOMINAL SECURING HOLE QUANTITY: 1 SCREW THREAD SERIES DESIGNATOR AND LOCATION: SINGLE HOLE UNC SECURING HOLE TYPE AND LOCATION: THREADED SINGLE HOLE NOMINAL THREAD SIZE AND LOCATION: 0.312 INCHES SINGLE HOLE MATERIAL: STEEL STYLE DESIGNATOR: A1 PLAIN ROUND