Drill bit--Tungsten solid Carbide twist drill bit 1)high quality, competitve price. 2)high precision 3)best material Drill bit--Tungsten solid Carbide twist drill bitUse featuresTwist drills are used for processing structural steel, stainless steel, alloy steel,gray cast iron,nodular cast iron, short cut non-ferrous metals and nickel base alloy,titanium alloy and ect material;strongly mark with ...