coated abrasive comprising a backing and abrasive grain adhered to said backing by means of a binder . the binder is prepared from a composition that is curable by free - radical polymerization . the composition contains abrasive grain suspended therein at the time the composition is coated onto the backing . the abrasive exhibits high endurance for extended periods of use . the coated abrasive is prepared by a method comprising the steps of : providing a coatable composition comprising a binder curable by free - radical polymerization , said composition having lapping size abrasive grains suspended therein , coating said composition on a backing , and curing said composition by means of free - radical polymerization .