[LESS DRILL BITS WITH MORE SIZES]:This high-speed steel step drill bit set includes 5 step drill bits with 50 sizes.-by-step design of drill bits allows it to gradually expand in a hole, meeting drilling needs for different diameters. drill bit does not need to be replaced when holes with different diameters are machined. [HIGH WEAR RESISTANCE]: This set is made from high-speed steel and combined with titanium coating, providing the drill bits with excellent wear resistance and heat resistance.3x longer life with uncoated step drill bit. [118 SPLIT POINT TIP & SIZES MARKING]: The 118 split point tip can minimize friction and resistance during the cutting process, thereby improving cutting efficiency. The laser-etched size markings provide positioning assistance for precise drilling, making the operation more user-friendly. [WIDE APPLICATIONS]: This step drill set is not only suitable for metal processing, but also can be used for drilling holes in wood, plastic and composite materials. Whether you are a professional machinist, carpenter, or a home DIY enthusiast, you can from it. Colour:As Shown Material:high speed steel Package Contents: 5 * step drill bits Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.