Carbide Tipped (TCT) Tungsten carbide is about twice as hard as steel, with a Young's modulus of approximately 530,700 GPa (77,000 - 102,000 pounds per square inch) and a density twice that of steel, almost midway between lead and gold. Its hardness is comparable to that of corundum (α - Al₂O₃). Carbide tipped bits are specifically designed to drill cleanly in end - grain wood and thin boards. They are ideal for drilling holes for concealed hinges and door locks. Curve Design In terms of curve design, the bits are good at clearing chips and have high working efficiency. Features 1. Forstner bits can drill clean holes in both softwood and hardwood. 2. With two cutting tips and a centering point, they can perfectly solve the problems of repeated, clean, and precise drilling again and again. 3. The sharp center cutting tip can accurately determine the center of the hole. 4. They are used to drill precise flat - bottomed holes in softwood of any thickness without chipping. 5. They can drill in any direction and can also be used to create arched openings. They can also drill partially overlapping flat - bottomed holes for tenoning. 6. They need to be used with an electric drill, and the drill is not included here. Precautions 1. When drilling, Forstner bits can only rotate clockwise and should not be reversed. The rotation speed should be gradually increased from low to high. 2. Please grind the cutting tips and the bit to avoid aging and damage when the bit is damaged. Otherwise, the precision and quality of drilling will decline sharply after the bit is damaged. Specifications - **Product Name**: Forstner Bit - **Material**: Carbide Tipped (HRC.70) and Carbon Steel Shank - **Packaging Specifications**: 1. 5 - piece set: 15mm, 20mm, 25mm, 30mm, 35mm 2. 11 - piece set: 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm Size Table | Size (D) (mm) | Total Length (L1) (mm) | Shank Diameter (d) (mm) | Shank Type | Shank Length (L2) (mm) | Maximum Cutting Depth (mm) | | ---- | ---- | ---- | ---- | ---- | ---- | | 15 | 80 | 8 | Round | 22 | 55 | | 16 | 80 | 8 | Round | 22 | 55 | | 17 | 80 | 8 | Round | 22 | 55 | | 18 | 80 | 8 | Round | 22 | 55 | | 19 | 80 | 8 | Round | 22 | 55 | | 20 | 80 | 8 | Round | 22 | 55 | | 21 | 80 | 8 | Round | 22 | 55 | | 22 | 80 | 8 | Round | 22 | 55 | | 23 | 80 | 8 | Round | 22 | 55 | | 24 | 80 | 8 | Round | 22 | 55 | | 25 | 80 | 8 | Round | 22 | 55 | | 26 | 80 | 8 | Round | 22 | 55 | | 28 | 80 | 8 | Round | 22 | 55 | | 30 | 80 | 8 | Round | 22 | 55 | | 32 | 80 | 8 | Round | 22 | 55 | | 35 | 80 | 8 | Round | 22 | 55 | | 38 | 80 | 8 | Round | 22 | 55 | | 40 | 80 | 9 | Round | 22 | 55 | | 42 | 80 | 9 | Round | 22 | 55 | | 45 | 80 | 9 | Round | 22 | 55 | | 48 | 80 | 8 | Round | 22 | 55 | | 50 | 80 | 9 | Round | 22 | 55 | | 53 | 80 | 9 | Round | 22 | 55 | | 55 | 80 | 9 | Round | 22 | 55 | | 60 | 80 | 9 | Round | 22 | 55 | | 65 | 80 | 8 | Hexagonal | 22 | 55 | | 70 | 80 | 8 | Hexagonal | 22 | 55 | | 75 | 80 | 8 | Hexagonal | 22 | 55 | | 80 | 80 | 8 | Hexagonal | 22 | 55 | | 85 | 80 | 8 | Hexagonal | 22 | 55 | | 90 | 80 | 8 | Hexagonal | 22 | 55 | | 95 | 80 | 8 | Hexagonal | 22 | 55 | | 100 | 80 | 8 | Hexagonal | 22 | 55 | Our products are made from the highest - quality materials and are designed to provide you with the best user experience. We strive to ship orders within three days of purchase, with an estimated delivery time of 8 - 15 days. When shopping, please pay attention to the product's size specifications to ensure they meet your needs. We have provided detailed information about the product, including its features and specifications, in the title and description. We hope you are completely satisfied with your purchase. If you have any questions or concerns, please feel free to contact us. We will serve you whole - heartedly and do our best to help. Thank you for choosing our products. Have a great time using them!