100% new and high quality feature: HSS steel, coated with titanium for friction and heat. The ladder of its unique structure, a little can a variety of specifications of the opening. Do not use the middle punch, more durable compared to traditional dispute drilling. Explode, edge, elliptical hole extension, twist drill, drill, table drill. Suitable for cutting holes in different materials such as steel, brass, wood, plastic, etc. Ideal for use in hardness under 25 artifacts, the plate thi