You receive 30 pieces of cobalt drill bits, double-ended, drilling diameter 1/8 inch, enough quantity to meet your daily use needs; please pay attention to control the speed, pressure and heat when applying the drill bits Suitable size: Twist double drill bit set is about 1/8 inch in diameter and about 1.89 inches / 4.8 cm long, M35 carbide cobalt double drill bits are the right size and easy to match with other drills such as lithium drills, electric drills, hand drills, impact drills (excluding) etc. Reliable to use: The cobalt drill bit is mainly made of M35 contains cobalt, which is strong, heat-, wear-, reliable, and has a long service life; because the is hardened and ground, the drill bit has accurate cutting operation and no need to worry about shaking Double-ended twist design: Each drill bit has 2 cutting points. You can use the cobalt drill bit set to drill 2 holes at each end to improve drilling efficiency; the cobalt drill bit adopts a 135-degree split point and twist design to increase cutting speed and drill holes. Accurate Wide application: M35 high-speed quenched steel drill bit is a good choice for drilling in hard metals such as stainless steel, cast iron, hard plastics, titanium alloys, wood, etc. It is also suitable for some soft materials Colour:Photo Color Material:M35 contains cobalt Package Contents: 30 x Double end cobalt drill bits Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.