This countersink drill bit set is designed to create accurate pilot holes and smooth screw countersinks in a single operation. The set combines HCS four-blade countersink cutters with M2 high speed steel tapered drill bits, delivering stable cutting performance and efficient chip removal. The adjustable aluminum depth stop allows precise control of drilling depth while protecting the work surface from excessive drilling. Compared with traditional stop collars, the bearing design reduces wear and helps maintain consistent drilling depth. With multiple sizes included, the wood drill bit set supports a wide range of screw sizes used in woodworking projects. The countersink drill bits create clean 82 degree countersinks that allow screws to sit flush with the material surface. Suitable for natural wood, plywood, MDF, particle board, and decorative boards, this drill bit set is a practical addition to woodworking tools used by carpenters, cabinet installers, and home improvement users.