Micro thread mills - WhizThrill

Featured Product from WhizCut of Sweden AB

Micro thread mills - WhizThrill-Image

Selecting the Correct Micro Thread Mill

1. Partial Profile VS Full Profile

  • Partial profile thread mills are better for long threads, tougher materials, and unstable machining conditions.
  • Full profile thread mills are better when tight tolerances of major and minor is required. Cycle time should be reduced, and a completely burr free part is the needed.

2. Grade VS Material

    • WhizThrill have an uncoated grade 9M, a sub-micron carbide ISO K20-K30. Performs well in soft materials where no coating is needed.
    • B9 is an AlCrN coating which gives an extra edge sharpness. Tool life will be 4-5 times longer in for example titanium compared with an uncoated tool.

3. Determine Length

  • Micro thread mills lose a lot of rigidity with increased length. Therefore, always choose the shortest possible tool.
  • WhizThrill has a 15° exit angle from the minor dimension (D) to shank (d). When possible, make the chamfer before thread milling so that you can calculate the length of the thread from the end of the chamfer.


10 benefits of thread milling vs. thread tapping. 

  1. The even cutting forces results in a thread profile that conforms through the entire length of the thread.
  2. Thread mills threads blind holes.
  3. Cutting conditions for thread mills are ideal. A rotational movement is matched in with a movement in a bigger rotation giving even and small cutting forces.
  4. Forget long and stringy chips. They are small and short when thread milling.
  5. WhizCut has increased the stability of the thread mill. A tapered neck leaves more room for chips at the head - where it is needed. At the critical point, where the neck meets the shank it is more stable.
  6. The tool life of a thread mill is often 5-10 folded of a tap.
  7. WhizCut can custom make micro thread mills that, in the same threading cycle, deburr both the top and the bottom of the thread.
  8. Thread mills rotates the same way continuously giving less stress to spindles and bearings.
  9. With small threads and tough materials the cycle time of the threading can be reduced considerably.
  10. At the end of the tool life, the micro thread mill will make the thread out of spec or in worst case it is broken. With a micro tap - the thread is out of spec or the tap is stuck in the work piece, rendering in a possible scrapped work piece.