Made from HSS 4241 high-performance steel 3 drill bits with the following sizes: 3-4-5-6-7-8-9-10-11-12 mm, 4-6-8-10-12 mm, 4-6-8-10-12-14-16-18-20 mm The edges of the drill hole remain clean and burr-free, automatic centring on rounded and slippery surfaces Fast heat dissipation when drilling into hard materials, 2 spiral chip grooves for efficient dust removal, Weight: 0.220462262 pounds, Manufacturer: Yato