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47% off 10pcs 0.3mm to 1.2mm PCB Print Circuit Drill Bits Only US $3.69 Shipped@Yesfor

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Hi all,today we are offering this set of Drill Bits for you only $3.69 with free shipping.

Description:
10pcs carbide micro drill 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2mm,
Drill has a large scraps discharge space, little resistance and smoothly during the scraps discharge.
Use high quality materials and fine grinding process makes bit more sharp cutting edge, reduce cutting force and broken drill, improve the quality of hole wall.
The cutting edges strictly avoid partial hole, ensure the quality.
It can drill 2000-5000 pcs under normal working conditions,also can return grinding 4-5 times
Shank diameter: approx. 1/8" (3.175mm)

Included:
10 x Drill Bits

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closed Comments

  • WTF is that description?
    Looks like a cheap set of cheap bits…

    • Agreed, it is quite poorly worded. The features mentioned, although poorly described, are desirable features if you have a high-speed computer-controlled drilling machine.

      I'll try a rough guess at what they are trying to say:
      - large flutes for fast chip clearance and reduced clogging
      - precision-machined tungsten carbide drill bits
      - lifespan of 2000-5000 holes drilled, if used in a high-speed (50,000RPM+) computer-controlled drill
      - designed so drill won't snap part-way through drilling a hole
      - can be re-sharpened up to five times

      Drill bits like these are excellent tools, but need to be handled with extreme care. Usually the drills are solid tungsten carbide, which snaps VERY easily if you put ANY sideways force on them. Treat them as though they are made of glass and you will get reasonable life out of them. ALWAYS wear eye protection if using with Dremels and the like, when they do break they really do shatter into multiple pieces, and the shards are really sharp.

      I only ever use drills like this in a pin vice (looks rather like a big jeweller's screwdriver, but takes drill bits), and anything below 0.8mm diameter I would expect to get ten or fewer uses before they snap. Mostly I use them to enlarge holes in a printed circuit board, if the existing hole is too small for a component lead.

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