Stripped thread

[Scouseget]

Yep, despite everyone who's ever worked on a watch telling me to be careful, I still managed to strip a thread in a watch currently undergoing servicing, and yes, it was indeed a left hand thread. I'm stymied as to how to effect a repair on this as my miniature tap and die set doesn't include a left hand tap of any size, let alone the one I actually need.

Any advice that works will be most appreciated and is worth at least one beer, or even a case of beer if it works really well and is fairly easy to do.

Yours in embarrassment - Roger from Edmonton. 

[jdm]

Even if you could find a correct tap, the damage is done, material won't go back. At this point either you keep it as it is, maybe try a tiny piece of wire or foil to improve grip. You could try threading and fitting a larger screw, but for a beginner even that is easier said than done, 

[clockboy]

As JDM posts out a difficult repair. Either re-tap to accommodate  a larger threaded screw or drill & fit a bushing & re-thread the bushing. The easiest way would be to find a donor moment. PS what is the movement.

[StuartBaker104]

If your name is George Daniels, you would doubtless make a new part... but in your case a drill and bush may be more appropriate. If you have time and a sense of humour then Daniels describes how to make yourself a left hand tap. It strikes me that you could skip the step of making a die and then a proper LH tap for a one-off repair:

Alternatively, if the screw you need is readily available you could buy a replacement to grind as described above to make a tap.

Edited December 17, 2017 by StuartBaker104

[rodabod]

You could also make a tap using a left handed screw of the correct width and preferably slightly longer than the screw to be fitted (I presume this is for a crown wheel?). 

[rogart63]

The easiest is probably to find a new part.