The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Thread damage problem in unmasking

2003

Dear Sir,

My company's line of business is in Aerospace.

This picture by looking at it looks like a turning thread problem but the turning dept. is telling us it was from the chemical attack that causes this. We only did acid etching for machine abuse and hard chrome on other surface parts and not on the threads . For hard chrome , all the surface includes the thread are fully waxed leaving the bare surface to be plated.

 

I need your kind help and your opinion.

Thank you

Yours Faithfully,

Tessensohn Albert
- Singapore

---

Been there, done that. Do your people remove the last of the wax or paint maskant with razor blades or an X-acto knife? My people have done just that ... it wasn't in the racking or shipping but the unmasking where such damage is likely to occur.

Also, if a coarse thread is forced into a fine thread, we've seem such damage. This would be similar to forcing a thread gage that was misaligned.

Anyway, it doesn't look like a thread cutting or forming issue. I would be that this defect occurred after the threads were initially cut.

Hope this is helpful and good luck with your investigation...

Milt Stevenson, Jr.
Syracuse, New York
2003