HSS Titanium Coating - High speed steel along with titanium coating ensures outstanding durability and sharpness, can reduces the friction, runs cooler. Meet Your Demands - With the step drill bits we offered, you can process different kinds of diameter holes, which greatly saves you a lot of trouble.Great for metal/wood/plastic countersunk. Suitable for Home DIY, and General Building/Engineering Use. Design - The split point tip is at 118 degrees to increase the wear resistance. The two flute design provides a smoother cutting, allows the material particles escape easily for a much more clean drilling operation. Easy Organizing - A drill bits holder with size index is included in the metal kit for easy storage and organizing without fear of it falling out. Set Includes - The drill bits set includes five common sizes for versatility, can fit the majority of brands currently on the market.