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Checking Thread Depths

William Krueger - Xometry
William Krueger - Xometry Posts: 16 admin
edited August 14 in Hangout

One of the most preventable problems we see with parts coming into our inspection department involves thread depths. This is when a thread does not fully engage to the depth in the drawing, and this is the leading cause of part rejections. We hope this video serves as a helpful reference.

We also have a full-proof 3-step process to ensure your thread depths are perfect every time:

  1. Check the part immediately for burrs and chips at the bottom of the hole. 
  2. Holes should be clear and free of oil and threads should look sharp.
  3. Check threads with a calibrated thread gauge. 
  4. The "Go" side should easily go all the way into the hole and should not bind. The "No-Go" side should not turn more than 2 revolutions.
  5. Check thread depth with calipers and a mating piece, a Go/No-Go gauge, or, if the hole is deeper than the gauge allows, an off-the-shelf screw.
  6. Insert the mating piece, Go/No-Go gauge, or screw into the threaded hole. Use calipers to measure the depth of the above item engaged in the hole to determine the depth of the hole.

Do you have any tips and tricks for checking thread depths? let us know in the comments below!


  • TexasTad
    TexasTad Posts: 7

    Take the Go-Gage out of the handle, check it's length, record this value, thread till it stops, use a depth gage against the back of the thread gage and reference surface, record this value - compare the two against each other. That's your thread depth :)