✅ Two-fluted design provides faster,smoother cutting, provided with small pressure and the sets. ✅ The 3-flat shank titanium drill uses a doubleedged design to make cutting smoother and smoother;Increases cutting speed with self-centering and prevents walking. ✅ Perfect for home repairs and light jobs such as drilling holes in plastic, aluminum, copper, iron sheet and many other types of sheet metal (excluding steel or any other harder metal). ✅ Classic High Speed Steel With Titanium Coating For Proven Capability and Durability. Increases Cutting Speed With Self-Centering And Prevents Walking. ✅ CORTOOL step drill bits are made of 100% genuine HSS 4241 steel, please be cautious of cheap substitues of low quality. Your customer satisfaction and 30-day warranty of step drill bit can be guaranteed.