[SIZE]- Twist drill bit with 0.8mm / 0.03 inch shank. [MATERIAL]- Diamond coated high speed steel(HSS) is made by spiral technology, has both toughness and hardness, is not easy to break. The drill bit is , and is easy for chip removal. [APPLICABLE MACHINE]- Widely used in rotary tool such as hand drills, drill , flex shafts, bench drill and hanging mill. [APPLICATION]- Suitable for drilling small holes on glass, metal, sea shells, jade, , marbles, stones, drywalls and son on. Due to the different hardness of the material, the effect is also different. [NOTICE]- When drilling, it is necessary to add cutting fluid in time to lubricate and cool down, which can get a better drilling hole wall, extends the service life and drilling accuracy. Colour: silver Material: Diamond Package Contents: 60 x Diamond Twist 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.