【HSS Twist Bits】- Made of high-speed steel with titanium coating, features high hardness, abrasion resistance, and durability, excellent heat dissipation during drilling. 【Round Shank Mini Drill Bits】- 1mm and 1.5mm bits should be used with pin vise to avoid drill bit break, 2mm to 3mm bits can be used with a rotary tool(Not fit with impact drill), only with low speed and low drilling pressure.
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