CNBTR Solid Carbide Milling Bites High-Speed HSS 4 Flutes Straight Shank Cutter End Mill with 2mm Cutting Dia Pack of 5 Can be processed stainless steel , die steel ,spring steel ,alloy steel, also suitable for cast iron ,iron ,copper and aluminum pieces High-speed steel Suitable for most general purpose applications Long durability and corrosion resistance It is made of high quality HSS and durable