1.Size - Drilling Diameter: 0.228'; Drilling Length: 65mm / 2.56'; Total Length: 98mm / 3.86'; Package Content: 12 x Cobalt Drill Bits. 2.Material - The twist drill bit is made of high-speed steel (HSS) and cobalt (CO), which has high hardness and sharper cutting, which helps to improve processing accuracy. It has good wear resistance, maintains stable cutting performance under high-speed rotation and high-temperature environments, and is not easy to deform. The surface is smoother after baking, which reduces the friction resistance between the tool and the workpiece and improves the cutting efficiency. 3.Features - The spiral groove design can effectively discharge the cutting chips generated during the processing and reduce vibration and material jamming. The 135° split point tip design has a strong self-centering ability, which is conducive to fast and accurate positioning on the workpiece surface, fixing the drilling position, and effectively avoiding displacement during the drilling process. 4.Application - Twist drill bits can be used with various clamping tools, such as hand drills and bench drills, and are suitable for drilling needs such as metal processing, auto repair, woodworking, and home decoration. They can be used for drilling operations in a variety of materials such as metal, wood, plastic, etc.