High Hardness and Anti-RustThese hex taps are made of high-speed steel with nitrided surface treatment for high hardness and anti-rust. Spiral Fluted Design: Tap with drilling function for drilling and tapping new threads and tapping. Ideal for drilling, tapping and deburring/removing soft metals, aluminum sheet, iron and more. Automatically More Accurate and More EfficientSelf-centering point, no need for an auxiliary center to drive the hole or hole center, more accurate, eliminate human error, save processing steps and time costs, and improve work efficiency. Anti-Wear: Taps are installed on the back of the cone to prevent excessive drilling caused by thread damage. 6 Different Sizes from M4 to M8: The 6.35mm quick change taps are engraved with inch size hex shanks to meet your different needs.