I have a few hairsprings that are ok but the hairspring has broken off.How hard and what is the method to pin a hairspring?
Are these still available?

Kevin "Veritas" West
IHC Member 261
Chapter 111,Ottawa
NAWCC Member 158976,
Nepean, Canada

Hi Kevin, forgive me, but I am a little confused. To me "hairsprings that are OK" and "hairspring has broken off" seem mutually exclusive. Do you still have the original stud? Most of the American companies seemed to settle on their own distinctive hairspring stud, so you will need to either have the original stud or an appropriate replacement. The spring can be re-pinned in the stud -- fine brass taper pins are made for this purpose and are available from the supply houses. But, if the spring has broken it will now be too short and the watch will run fast. If it is a flat hairspring perhaps you can add timing washers or swap to heavier timing screws to make up the difference (although this may throw off temperature compensation). If it is a Breguet hairspring, then the overcoil may need to be adjusted as well. I am sure there are other points that need to be considered that some of our more technically advanced members can comment on.

I guess what i meant is yes the hairspring had broke , but it was broke not far from the stud, so i figured it could be repaired as to having to change it.
I do have the stud.I need to get some puches i guess.If the watch is not worth much money would it still be worth it to try to slow it down?

Kevin "Veritas" West
IHC Member 261
Chapter 111,Ottawa
NAWCC Member 158976,
Nepean, Canada

[Preface - my advice is not based on watchmaking school, but on my own trial and error technique over a number of years.]
First you will need some way of holding the stud while you work on it. Bergeon, and probably others, make a tool specifically for holding the stud while re-pinning the hairspring, but you can use the balance cock for this purpose. An advantage to using the original balance cock is that it will hold the stud snugly and will show you if the collet is still on center (over the hole jewel) as you progress with your repair. You will need to remove the hairspring with collet from the balance wheel.

You can use a sharpened fine steel needle to push out the old pin and remnant of hairspring. (I don't think you need any punches). If the hairspring does not have an overcoil it should be a simple matter to insert the end into the stud and pin it with a new taper pin. Then make sure the outer arc of the spring matches the arc of the regulator pins and the collet is still over the center. If you did not lose much spring it should be pretty close. As you pin the spring make sure it remains flat relative to the cock and does not tilt up or down. You should be able to bring the watch back to reasonable time-keeping with dial washers. If the hairspring had an overcoil you may need to do further adjustment to the spring to match the arc of the regulator pins and to keep the spring true. (Again, others more technically trained may wish to add to this, or even correct me).

Kevin,
I asked a similar question about hairspring studs back in September. The string still appears towards the bottom. You might want to check it out also. I bought my hairspring studs at Dash-to. I was not able to find them at S Larose or other catalog suppliers.

I still have not attempted to stud a hairspring. I am seeking a studding table, but Dash-to has some that appear to look different. I am not sure how to use one and waiting until I read more about that.

Thanks Willy i will have a look at Dashto, there are a lot of tools and parts and other things to look at on that site.
Do you have quite a few watches that need this repair i have only a few of them, including a few swiss i think.

Kevin "Veritas" West
IHC Member 261
Chapter 111,Ottawa
NAWCC Member 158976,
Nepean, Canada

I have a couple. I need to completely replace the hairspring on one watch and I may have to move the stud's position on the spring, so that it has the proper vibrations. I also have one that broke, that will need a new spring. I've got a couple of others that I bent out of shape and will need to be bent back.

I have the Chicago School of Watchmaking Correspondence booklets. A copy can be gotten from Uncle Larry's. There are three lessons dedicated to hairspring work. I want to study these further before making any attempts.

Jerry,

Did you mean "timing washers" instead of "dial washers"?

John D. Duvall
Vice President, Education

Boy, do I feel silly . John, thank you for the correction.