Includes 3 Different Sizes And Easy To Drill: Set Of 3 Titanium Coated Hss Taper Drill Bits (4-12Mm, 4-20Mm And 4-32Mm). Comes With A Cotton Storage Bag. Two-Flute Design Provides Faster, Smoother Cutting; Supplied With A Little Pressure And The Sets Can Cut Through Wood, Sheet Metal, Steel And Other Surfaces. Stepped Taper Drill Bits For Drilling Various Size Holes From 4Mm To 32Mm In Diameter, Optimum Speed And Accuracy.Titanium Hss And Application: Classic High Speed Steel With Titanium Coating For Proven Capability And Durability In The Drilling Holes In Plastic, Aluminum, Copper, Stainless Steel And Many Other Types Of Sheet Metal. The Titanium Drill Bit Is Particularly Suitable For Processing Copper And Aluminum Parts, Cast Steel, Spring Steel, Cast Iron Parts, Iron And Other Metal Materials.Material: Holes Perfectly Rounds Of Steel, Brass, Plastic, Wood, Copper, Fiberglass, Pvc, Fine Metals And Aluminum. Heat Treated And Highly Polished, Titanium Coated To Reduce Friction And Heat.Tri-Slat Shank: Inserts Securely Into Power Tool Chuck And Eliminates Slippage.