1. 6 Sizes: 3mm, 4mm, 5mm, 6mm, 6.5mm, 8mm, total quantity is 6 pcs.
2. Mainly for thinner, low hardness of wood and soft metal hole processing, for high hardness stainless steel and other materials can not be processed.
3. The main material is high-speed steel, with titanium and nitriding treatment. High speed steel is more abrasion resistant and durable than other metal materials.
