Wrenches features: High hardness, rustproof, solid and durable. Do not need additional center drilling or center punching. Fast replacement composite cone, uses drill edged principle. Drilling and tapping in one, one-step processing, greatly save processing steps and time costs, improve working efficiency. The automatic center punch delivering an automatic spring-driven strike when pressed against surface, it can be adjusted regulates striking force. Suitable for drilling, tapping, cutting on metal, aluminum plate, iron, etc. Features Color: Black Material: Steel Size: 7.00 x 1.20 x 1.20cm/ 2.75 x 0.47 x 0.47 inch Say bye to all those chips and particles, with the design the drill bit can quickly clears them out, and leaves a clean, smooth hole Back tapered beyond tap to prevent thread damage from over-drilling Maximize efficiency with the included quick change adapter that allows you to switch between different sizes easily Fast replacement composite cone, uses drill edged principle Drilling and tapping in one, one-step processing, greatly save processing steps and time costs, improve working efficiency.