Fangrui Product Details Hss6542 Double Cutting Blades: Engineered For Precision, Our Step Drill Bits Double Cutting Blades That Ensure Smooth, Fast, And Accurate Drilling. The 118 Split Point Tip Enhances Cutting Speed And Prevents Deviation, Making It Ideal For Various Materials Including Metal And Wood. Durable Titanium Coating: Each Bit In This Set Is Coated With Titanium To Enhance Durability And Reduce Friction. This Coating Not Only Extends The Life Of The Bits But Also Enables Smoother Cutting Through Tough Materials, Ensuring Efficiency And Longevity In Your Drilling Tasks. Versatile Applications: For Diy Enthusiasts And Professionals Alike, These Bits Are Suitable For Drilling Through Plastics, Aluminum, Wood, And Iron. For Optimal Performance, Especially In Metal, Use Coolant And Maintain A Moderate Speed To Prevent Overheating. Comprehensive Set For Multiple Needs: This Set Includes Three Bits With Varying Step Sizes To Cover A Wide Range Of Drilling Needs. From 4mm To 32mm, These Bits Are Designed F