5-piece Countersink Drill Bit Set — precise, durable, and easy to use Key benefits Control and consistency: Adjustable stop collars let you set exact drill and countersink depths to avoid over-drilling and achieve uniform, flush screw heads. Faster, cleaner drilling: Cone-shaped cutting geometry speeds chip evacuation, reduces clogging, and increases drilling efficiency. Quick size identification: Five color-coded bits make it simple to pick the right size at a glance and reduce setup time. What’s included and sizes Five color-coded countersink bits: Red — ≈ 2.8 mm (0.11 in) Yellow — ≈ 3.0 mm (0.12 in) Dark blue — ≈ 3.2 mm (0.13 in) Green — ≈ 3.5 mm (0.14 in) Purple — ≈ 4.0 mm (0.16 in) Materials and performance Built from premium 40CrV alloy steel with high-speed steel cutting edges for improved strength, wear resistance, and longer tool life. Optimized cone profile clears chips quickly to prevent clogging and maintain cutting performance over repeated use. Compatibility and applications Versatile for: wood, plastic, fiberboard (MDF), soft metals and aluminum alloys. Ideal for creating pilot holes and countersinks for screws, installing hinges and hardware, and general woodworking or light metal fabrication. Practical use scenarios Furniture assembly: Drill accurate pilot holes and countersinks so screw heads sit flush for a clean finish. Cabinetry and door hardware: Set a consistent countersink depth for hinges and fittings to ensure reliable alignment. Plastic enclosures and light metal work: Make neat, burr-free entry holes and countersinks when working with plastics or thin aluminum alloys. Why choose this set Simple depth control and color-coded sizing reduce errors and speed up common tasks. Robust materials and efficient cutting geometry deliver reliable performance across a range of materials. Note: Adjustable stop collars provide repeatable depth control; check fit and bit-to-drill compatibility before use.