TUNGSTEN CARBIDE TIP(TCT) Tungsten carbide is approximately twice as stiff as steel, with Young's modulus of approximately 530700 GPa (77,000 to 102,000 psi), and is double the density of steelnearly midway between that of lead and gold. It is comparable with corundum (-Al2O3) in hardness. Tungsten Carbide tip is specially designed to cut through holes cleanly in end grain and thin stock, great for boring concealed hinges and door locks. DESIGN WITH CURVE In a design with curves, the head is good at removing the debris and working efficiently. Features 1. Forstner Bit drill clean holes in soft and hardwood. 2. Two spurs and centering point to give the perfect solution to repeated, clean and accurate hole cutting time after time. 3. The sharp center spur accurately locates the center of your hole. 4. Use to drill precise flat bottom holes with no chipping in any thickness of soft wood. 5. For drilling holes in any direction and making arched openings. For drilling partially overlapped flat bottom holes for easy mortising. 6. Should be used with a power drilling machine, here is not included. Please Note: 1. When drilling holes, the Forstner drill bit is made only in the clockwise direction, not reversible, and the speeds from low to high are a gradual process. 2. Please grind the tool nose and tips to avoid aging and damage when breaking, or it will cause a steep decrease in accuracy and quality for drilling holes after the tips break. Specification: Product Name: Forstner Bit Material: Tungsten Carbide Tip(HRC.70) and Carbon Steel Body Package: 5pcs =15mm,20mm,25mm,30mm,35mm 11Pcs=15mm,20mm,25mm,30mm,35mm,40mm,45mm,50mm,55mm,60mm,65mmSize Chart: Size (D) Overall Length (L1) Shank Dia. (d) Shank Type Shank Length (L1) Cutting Depth Max. mm mm mm mm 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 Hex 22 55 70 80 8 Hex 22 55 75 80 8 Hex 22 55 80 80 8 Hex 22 55 85 80 8 Hex 22 55 90 80 8 Hex 22 55 95 80 8 Hex 22 55 100 80 8 Hex 22 55