Description: Suitable for drilling, tapping, cutting on metal, aluminum plate, iron, steel plates, even 304 stainless steel plates of about 2mm etc. Quick change 1/4" (6.35mm) hex shank with metric sizes engraved on the bits. Wide spiral flutes carry the chips out of the hole. Can be used on multi-spindle heads with reversing mechanisms for tapping in most materials. Drilling and tapping in one, one-step processing, greatly save processing steps and time costs, improve working efficiency. Self-centering point, do not need assistant center drilling or center punching. Made of high quality HSS 6542; High hardness, rustproof, solid and durable. Specification: Material: HSS Shank diameter: 6.35mm hex shank(1/4") Color: silver Package Includes: 1 piece combination drill tap(6 Pack) Note: Color might be slightly different due to the color calibration of each individual monitor. Please allow slightly measuring deviation due to manual measurement.