Fangrui Product Details 4pcs Countersink Drill Bit Set: Carbide Countersink Drill Bit Set For Wood Includes 4 High Speed Steel (hss) M2 Drill Bit Tapered Heads In Sizes Of 1/9x1/3inch(2.8x8mm), 1/8x1/3inch(3.2x8mm), 1/7x2/5inch(3.5x10mm), 1/6x2/5inch(4x10mm), 82 Countersink And 1/4-inch Hex Shanks For Secure Clamping And Universal Compatibility With Most Drills, Its The Top Countersink Drills For Wood Depth Adjustable: The Depth Of Both Drill And The Countersink Can Be Adjusted With A Wrench To Adjust The Depth Limiter And Bit For Precise Drilling. The Added Plastic Collar Reduces Abrasion. : M2 Hss Counter Sink Drill Bit For Wood With Spiral Chipformer Ensures Fast Cutting; Steel Alloy Produces Smooth Countersinks And Countersunk Holes, For Installing 82 Degree Imperial (us) Standard Screws. Widely Usage: The Counter Sink Bit Is Suitable For Processing Natural Wood, Manufactured Lumber, Plywood, Particle Board, Drywall, Mdf, Decking And A Variety Of Plastic Boards. For Results And Smooth Edges, The Counter Sink