20Pcs 1mm Mini Micro Drill Bits Jewelry Drilling Bit Diamond Stone HSS DrillBits

Features: *Install the hole opener on the electric hand drill or small bench drill land use it. *Because this kind of hole opener has no center positioning bit the hole opener should be tilted at 45 the speed of electric drill should be slowed down and the glass stone should be contacted slowly. *Do not make the opening too fast. It is necessary to add water continuously to cool the opening device. *When drilling clean water is needed to cool the drill bit. Good cooling can significantly extend the service life of the hole opener. *Do not use the drill bit without water otherwise the drill bit may be damaged. *It is recommended to hold the drill bit deeper. If necessary you can cut off the drill bit to make it shorter so as to reduce shaking and not easy to break. *The drilling speed cannot exceed 6000 rpm because the drilling speed is too high the drill bit is easy to break. Specifications: Product name: Mini Micro Drill Bits Material: Diamond Stone Length: 40mm (Approx. ) Shank diameter: 0.6mm Drilling diameter: 1mm Color: Silver Suitable for: Jade Marble Handicrafts Quantity: 20 Pcs Package Contents: 20 Pcs Mini Micro Drill Bits Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data.