... Alloy mould: Diamond sand wheel. Hard alloy Alloy moulds: Grade : J101,J901,F23,YWN15,YGX15,YGX1,YG8T,YG15C,YG20C 1:Characteristics of Alloy ... moulds:A: Hard alloy ... resistant to high speed repetitive impact.YWN15: The alloy is for moulds forming magetic products such as NdFeB ...