Broken screw removal

[lunacie]

I've had good luck with broken screws that had enough sitting above the movement plate that I could grab with a pin vise, but now have two movement plates with screws broken deep into their holes, which at least extend through the entire plate (though no part of the borken screw protrudes at either end).

Anybody out there have a sound way of getting these out without destroying the surrounding threads?

I've got some tools - Boley lathe with faceplate, lever feeding tailstock, I've got a flexshaft tool, some various and sundry taps & dies (rather meager selection, I admit), but would imaging that something here should work.


thanks,

john t.

 

[lunacie]

I've had good luck with broken screws that had enough sitting above the movement plate that I could grab with a pin vise, but now have two movement plates with screws broken deep into their holes, which at least extend through the entire plate (though no part of the borken screw protrudes at either end).

Anybody out there have a sound way of getting these out without destroying the surrounding threads?

I've got some tools - Boley lathe with faceplate, lever feeding tailstock, I've got a flexshaft tool, some various and sundry taps & dies (rather meager selection, I admit), but would imaging that something here should work.


thanks,

john t.

 

[Hank Grimmick]

I've seen advertised a Bergeon broken screw extractor. Never tried one, so I can't vouch for how well it works.

Regards,

Hank

 

[doug sinclair]

Lunacie,

If tools won't do the job, remove ALL steel parts from the plate, including dial screws, and whatever, and soak the plate in a solution of alum and water. It may take a few days, but that will eat the steel screw away and not touch the rest of the metal.

Doug S.

 

[michael h schneider]

If the screws aren't actually tight against anything, I'd be tempted to toss the plate in an ultrasonic and hope. They just might jiggle themselves out in one direction or the other. It probably won't work, but it won't hurt anything, either.i

 

[lunacie]

I ended up drilling the screws out by mounting the movement plate in a faceplate and turning it onto carbon drill bits in my lathe. Painful but effective.

I just reassembled the chronograph movement and found two other broken screws - the very last two in the reassembly process. ARGH! I can't believe I missed those, but there are so many tapped holes in this chronograph plate that it's hard see the forest for the trees.

Back to the lathe...


thanks for the suggestions,

john t.

 

[mrb]

a friend of mine used to place the movement on his watch lathe motor. when running the motor the vibrations often worked the screw out of the hole. i think this approach would have its limitations. i have often drilled a small hole into the center of the screw, tapped a piece of drill rod into the hole and then twisted it out of the hole. sometimes if the threaded hole is through the plate you can just turn it completely through the hole.

 

[lunacie]

I guess I need to strongly consider the Bergeon screw extractor tool, though it seems rather expensive, and everyone I've talked to has mixed feelings about it. OTO, most of the broken screws I encounter are accessible from both sides.

If anyone who's used the Bergeon screw extractor would like to comment on its effectiveness, I'd be grateful.

thanks,

jt