Material- Drill bit set made of premium HSS, HRC 62-64 hard material with excellent hardness and wear resistance. Wood drill bit set offering optimum cutting power, high durability and high abrasion resistance. Ideal size hole for #5, #6, #8, #10 or #12 screws. Standard 82 Angle- These countersink bits for pilot end screws are designed to match to the most commonly used 82 carpentry screws on the market. 1/4'' Hex Shank- Quick-change chuck works with hammer drills and other power tools. It perfectly meets all your daily needs. The product interface size is suitable for most household drills. Simple and easy to use kit for woodworking. Multi-Purpose- Suitable for home or professional woodworking, used on wood, plastic, PVC, fiberboard, particleboard, plywood, rubber and more. Drill, countersink and counter-drill in one step. 5-piece countersink countersink set Adjustable 1/4" hex shank with quick change Made of high-speed steel (HSS) premium quality for long life. Able to drill a pilot or pilot hole and countersink for the screw head or countersink for the connector in one step.< /p> Quick-change, precision-machined chucks are compatible with hammer drills and other power tools designed to take a 1/4'' hex shank. 82 Thread Standard The countersink angle of 82 matches the angle of the head of most screws you may encounter.This countersink set allows all surfaces of the screw head to make contact with the wood at the same time and with the same force. You won't have to forcibly lengthen the bit by applying too much force to the screw. Double Tool Life 5pcs Freely replaceable countersink bits, depth adjustable and removable for easy cleaning and replacement. Worn or blunt countersink bits can be easily replaced. L-wrench. Hexagon head screw Better fixation of the bit, to avoid that it won't come off or fall off.