The Diamond Grinding Wheel - Steel metal hubs are heavier which means more grinding force.Diamond Lapidary Grinding Wheel with steel hub Made with highest quality diamonds for longer grinding life, clean and faster cutting for cabochon machine,Lapidary equipment, lapidary supplies for rock-hounds and hobbyists,such as Cabbing Machines,Faceting Machines, cab lapidary machine and Lapidary Grinder Polisher.Can be used on all conventional grinders made today. Such as Hans,Diamond Pacific, Barranca, Maxant, Graves, as well as other cabbing machines suit for grinding hard materials ,They are particularly well suited for glass beveling, cold glass working and lapidary working, it has a 1" arbor comes with bushings to adapt to 1/2, 5/8 or 3/4 inch shafts. Available in a variety of grits and sizes.