Adopting high-quality material and fine polishing, this drill bit has higher hardness, better heat resistance and excellent percompatiblemance. Integral design makes this drill bit have high strength, spiral groove design makes it be conducive to chip removal and unique triangular design enables it to have large bite area and friction area, which is more practical. This drill bit is mainly made of the hard alloy, which is abrasion-resistant and durable. There are sizes of 3mm, 4mm, 5mm, 6mm, 8mm, 10mm, 12mm compatible you to choose. It is suitable compatible drilling works of ceramic, wood and other materials. Item Name: Triangle Drill Bit Material: Hard Alloy Shank Type: Triangle Shank Size Details: 3mm: Diameter: 3mm/0.12", Length: 80mm/3.15", Working Length: 40mm/1.57" (Approx.) 4mm: Diameter: 4mm/0.16", Length: 80mm/3.15", Working Length: 47mm/1.85" (Approx.) 5mm: Diameter: 5mm/0.2", Length: 80mm/3.15", Working Length: 47mm/1.85" (Approx.) 6mm: Diameter: 6mm/0.24", Length: 100mm/3.94", Working Length: 60mm/2.36" (Approx.) 8mm: Diameter: 8mm/0.31", Length: 110mm/4.33", Working Length: 70mm/2.76" (Approx.) 10mm: Diameter: 10mm/0.39", Length: 120mm/4.72", Working Length: 75mm/2.95" (Approx.) 12mm: Diameter: 12mm/0.47", Length: 125mm/4.92", Working Length: 78mm/3.07" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Drill Bit