High-Quality Cobalt Materials -- Countersink Drill Bits Are Crafted From M35 Cobalt High-Speed Steel, Provide Double Protection Fortified With A Cobalt Coating For Enhanced Durability, Corrosion Resistance, And Heat Resistance.This S Reliable Performance, Even In Demanding Applications. | | Efficient Cutting Design -- With A Five-Flute Design, These Drill Bits Offer Superior Stability During Cutting And Efficient Debris Discharge. This Design Extends The Blade Life, Ensures Accurate Cuts, And Speeds Up The Drilling Process. | | Versatile Applications -- Includes 5 Most Popular Sizes (1/4", 3/8", 1/2", 5/8", 3/4") And 1 Special Size 5/16". M35 Cobalt Countersink Drill Is Suitable For Stainless Steel, Carbon Steel, Iron, Copper, Aluminum And Most Other Metals As Well As Wood, Plywood, Etc. | | User-Friendly Design -- Featuring Laser-Engraved Step Sizes, Our Countersink Drill Bits Ensure Clear Visibility And Durability During Use. This Design Enhances Convenience And .