- This product is made of high speed steel and titanium material,Smooth surface finish, long service life. - Great replacement for your dull drill bit to improve work efficiency. - Straight shank design is more suitable for many electric drills (here is not included). - Particularly successful in cutting through hard metals such as stainless steel and cast iron, although they can be used for softer materials, too. - No center punch is needed—the 135° Quick-Cut points are self-centering and penetrate quickly with less pressure. Will not "walk" or "wander" - Shank Diameter: 4.2mm/0.17 inch - Drill Bit Length: 9.7mm/0.38 inch - Total Length: 50mm/1.97 inch Package Content: 10 pcs x HSS Twist Drill Bit Notice: - Please keep cool and gentle using, the working life of the twist drill bits can be largely prolonged by proper usage.