... carbide powder 4 DIN1897 standard or non tungsten carbide twist drill GradeCompositionGrain Size(um)Density(g/cm3)HardnessISO3738(HRA) ... carbide at 0.5um applying to glass fiber, wood ,plastic, aluminum-magnesium alloy and other materials processing .Recommended ... are processed reamer, aluminum alloy ,red brass, bronze , plastic etcJGK5085151.214.087.63100Suitable for the overall producing of stamping ...