tungsten carbide twist drill 1)Material:tungsten carbide and hss 2)High quality and reasonable price 3)Manufacturer tungsten carbide twist drill1)Material:tungsten carbide and hss2)High quality and reasonable price3)Manufacturer4) Super high hardness and precision, extreme smooth coating surface, can be coated by TIN, TIALN, ALTIN, TIAIN, etc.5) Excellent performance in some sticky metals cutting ...