[High Quality and Durable]Constructed from M2 high-speed steel with spiral grooves and steel alloy cutting edges, these countersink drill bits ensure smooth operation. The sharp edges provide precise countersinking, creating smooth and enlarged holes suitable for 82-degree British (US) standard screws. [Adjustable Depth Stop]Equipped with a depth stop and an L-shaped hex wrench, this countersink drill bit set allows precise control over drilling depth, protecting the surface from damage while ensuring consistent screw depths across various projects. [Comprehensive Drill Bit Set]This 4-piece set includes M2 HSS tapered cone drill bits in sizes 2.8MMx8MM, 3.2MMx8MM, 3.2MMx10MM, and 4.0MMx10MM. It's a versatile toolkit addition for professional and DIY projects alike, ensuring you have the right tool for different materials and applications. [Versatile Application]Ideal for a wide range of materials including all types of wood, aluminum, gypsum board, and plastic sheet materials. This set offers diverse drilling options, making it a must-have for carpentry, construction, and home improvement projects. [Optimal Operation Tips]For best results and to achieve smooth edges, it is recommended to operate the countersink at low speeds, around 200 RPM. This practice helps in achieving cleaner cuts and prolongs the life of the bits. Description/Features: The product is designed to meet the highest standards of quality and efficiency. It is crafted using state-of-the-art technology and materials that ensure durability and performance. Ideal for both professional and personal use, this product offers versatility and functionality that surpasses conventional alternatives. Specifications: Material: High-grade composite Technology: Advanced integration system Durability: Tested under rigorous conditions Usage: Suitable