High hardness and anti-rust] These hexagonal taps are made of high-speed steel, and the surface is nitrided for high hardness and anti-rust. Spiral groove design: Tap with drilling function for drilling and tapping new threads, smooth tapping. Ideal for drilling, tapping and deburring/demolition soft metals, aluminum sheets, iron, etc. Automatically more accurate and efficientSelf-centering point, no need for auxiliary center to drive hole or hole center, more accurate, eliminate human error, save processing steps and time cost, and improve work efficiency. Anti-wear: The back of the cone is covered with a tap to prevent excessive drilling caused by thread damage. : 1/4" (6.35mm) Quick Change Hex Handle Faucets are engraved with imperial dimensions to suit your different needs.