Restoration of Damaged or Dirty Threads

[StinkyPete]

This may be a well known "fix" but I learned it many years ago from a watchmaker.

Damaged Internal Thread
If you have a clogged or lightly damaged internal thread, and you don't have a tap of the right size, a spare bolt of the correct size can be used to fix it.   Simply file down part of the bolt thread as shown in the photo, and screw it into the damaged thread.   It will clear the accumulated crap and straighten out any minor damage to the thread.

Damaged External Thread
If you do't have thread dies, lightly damaged or clogged external threads can be cleaned/repaired using a thread file, as shown in the photo.  These have a series of serrations that are matched to thread pitches, and you simply run it over the damaged portion of the male thread.   See this video for info on use of a thread file.    https://www.youtube.com/watch?v=dYu_fl59Ztw

[cravenhaven]

Thanks for this post Pete. I had seen these tools in the past and never knew what they were for.
Now I know!!.

[Shiney]

Awesome info mate, thanks for sharing
This will come in handy