1. Set of 7: This long wood drill bit set includes bits with diameters of 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 10 mm, and 12 mm, each 300 mm in length, catering to all your woodworking needs. 2. : The long wood drill bit set is crafted from HSS and carbon steel, tempered and heattreated to enhance hardness and maximize the lifespan of the auger drill set. The hardness and exceptional wear resistance of the steel ensure load transfer through the shaft. 3. Precise Drilling: The angled tip of these professional auger bits enables faster drilling and smoother hole walls, making them ideal for deeper holes in both hard and soft woods. for carpenters, DIY enthusiasts, or professionals who demand precision in every detail. 4. Efficient Chip Removal: The spiral design of these professional auger drill bits ensures rapid drilling speed and smooth chip removal, minimizing clogging during drilling. This allows for continuous, clean, and smooth holes, boosting work efficiency and drilling quality.