Disc pad hub has a metal insert designed to fit right angle grinders with 5/8-11 external short shafts (3/8 Inch -1/2 Inch long) and can be used on most face plates. Use with 4-1/2 Inch to 9 Inch face plates
3M 60980031565 Disc Pad Hub, Retainer Nut, Diameter: 2-1/2 Inch, Thread Size: 5/8-11 UNC, Black For Additional Product Information, Click Here