[time-nuts] repairing Maser threads
Charles P. Steinmetz
charles_steinmetz at lavabit.com
Tue Apr 13 18:19:55 EDT 2010
>Another solution - especially with metric - is to tap the holes (
>only bad - or all - so that they all match) to the next larger
>Metric size - of the same thread pitch as original - so as not to
>cut across the original threads, but just cut the same thread pitch
>to the next size, such as from 5mm to 5.5mm or 6mm. Then you only
>have to buy a standard - not too expesive - metric tap - and some
>new slightly larger hardware.
Unfortunately, 5 mm is the only standard metric thread with a 0.8 mm
pitch, so you'd need a custom tap and would need to make custom
bolts. Hence, my suggestion to just make some custom bolts in
"M5.2x0.8" or "M5.5x0.8," whatever is necessary to get a tight
fit. Same approach, but less work (although if someone ever loses
the bolts, they'll go crazy trying to figure out what to use for replacements).
What I didn't mention previously, but would be good practice if you
went that way, is to cut one straight flute on the bolts (look at a
self-tapping machine screw to get the idea) to make it easier for
them to deepen the major diameter of the original 5 mm thread.
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