【High Quality Material】Titanium Step Drill. Twist drill bits made of high speed steel with titanium coating to reduce friction and heat, more capable and durable. 【Dimensions】3pcs step drill bit set which includes three different sizes of 4-12mm/4-20mm/4-32mm, to meet different drilling size needs. 【Anti-Slip Design】Titanium step drill bit set adopts groove design, helps the electric drill hold it more firmly, avoid slipping or falling during rotation. 【Efficient Operation】In the drilling process, the titanium step drill bit vibrates less than twist drill bits and has clear scale, wide and flexible application for easier work.