About This 【Complete 15PCS Countersink Drill Bit Set for Woodworking】 This all-in-one set includes 5 tapered drill bits (#4, #6, #8, #10, #12), 2 replacement bits (#4, #6), 2 wood plug cutters (3/8", 1/2"), 2 depth stop collars, 2 Phillips screwdriver bits (PH1 & PH2), 1 Allen key, and 1 bit extension shaft. Everything you need in one organized kit. 【Premium High-Speed Steel with Nitride Finish】 Each countersink drill bit is made from industrial-grade high-speed steel and coated with a nitride surface for maximum hardness, wear resistance, and durability. Built to drill clean holes in both softwood and hardwoods. 【Precise Depth Control for Perfect Finishes】 Includes adjustable stop collars and Allen key for fine-tuning drilling depth. Achieve consistent pilot hole depth and professional screw countersinking without damaging your work surface. 【Smooth Drilling & Clean Countersinking】 Tapered pilot bits create tight, accurate pilot holes, while the 82° countersink angle ensures smooth, flush screw seating. Wood plug cutters allow you to conceal screw heads seamlessly for a finished, polished look. 【1/4" Hex Shank Quick Change Design】 Designed for efficiency and compatibility, the 1/4" hex shank fits most standard drills and impact drivers. Perfect for cabinetry, furniture building, framing, decking, and general wood joinery projects. Overview Material : High Speed Steel (HSS) Finish Type : Titanium Nitride Shank Type : Hex Brand : ColumPRO Tool Flute Type : Spiral