Shaft Arbor Fits Shaft Diameter 1/2 in For Use With Smaller Fractional Horsepower Motors Includes Hex Nut Machined Washers Thread Length 1 13/16 in Thread Size 1/2 In.-20 LH Washer Outside Diameter 1 1/2 in Maximum Wheel Width 1 1/4 in Setscrew Type Socket Shaft Rotation Clockwise Overall Length 3 1/2 in Type Standard Application Mounting Various Buffing and Finishing Wheels on Electric Motors