3 Pieces 4 Inch Diamond Cup Grinding Wheel. Large grinding segments with heat treated cup design.The wheel diameter 4 inch and the arbor diameter 0.86 inch. 4 Inch grinding wheel 12 Segs heavy duty angle grinder wheels, made of high quality of diamond, use long life Perfect for use on grinding on marble, tile, concrete and rock. Use dry/wet to smooth concrete or field stone. 3 Pieces 4 Inch Diamond Cup Grinding Wheel. Large grinding segments with heat treated cup design. 4 Inch grinding wheel 12 Segs heavy duty angle grinder wheels, made of high quality of diamond, use long life Perfect for use on grinding on marble, tile, concrete and rock. Use dry/wet to smooth concrete or field stone.