[Diamond Drill Bit Size] Dry diamond drill bit set size included: 20pcs 6mm hole diameter drill bits with 1/4 hex shank, the length is 65mm. [Dry Drilling] which can melt and cool the cutting edge when dry drilling, you can also use as an additional coolant to extend the life of the drill bits. [Wide Application] The diamond hole saw sets have a wide application, you can use them to drill holes for your ceramic pots, also can be used in different hard materials such as: , tile, glass, marble, brick, stone, etc. [1/4 Hex Shank] The drill bits are hex shank which is more suitable for electric drill chuck, not easy to slip when working, improve work efficiency. [Friendly Reminder] In order to improve the life of the drill, it is recommended to open the small pressure groove Moon on the item at a 45 degree angle throughout the process at high speed, and then slowly erect the drill to 90 degrees Please note that the physical color difference or difference does not affect the use, please