Is Bergeon 1896-H a good tool to bore 0.15mm seconds hands to 0.18mm?

[kaan]

Hi everyone,

I've recently bought quite a bit of 0.18mm NOS seconds hands for Omega's, at close inspection, I think these are 0.15mm - I've attached a comparison shot, first 2 ones are the ones I bought, and the 3rd one is 100% 0.18mm used hand

So my question is, if I buy a Bergeon 1896-H set, which is easily available, can I bore these 0.15 hands slowly by testing and boring and testing and boring to be 0.18mm? - or is there a better tool for the job?

Regards and thanks in Advance,

Kaan

 

[Paul80]

One thing I would check before broaching is do they actually fit, the used one my be slightly larger because its been stretched larger through use.

Broaching my render the new ones unusable.

Back to you question, the Bergeon set of broaches would probably not do what you want as they are designed to open a hole in a plate, not a hole in a tube although they could be used to open both ends, leaving the middle of the tube slightly tight which may help fitment.

For a Bergeon tool they are not very expensive so it may be worth just buying a set and seeing if they will do what you are looking for.

 

[Waggy]

Hi there, I just did something similar this weekend where I used a set of cutting broaches (generic, not Bergeon) to open up the hole in the seconds hand. I think there may have been a slight manufacturing defect in the seconds hand, so maybe the broach just freed the obstruction rather than opening up the hole? As @Paul80 says the broaches are relatively inexpensive, and you will probably need them at some point in the future anyway, so it's worth a try. Just remember to take it easy, you can always open up more, but it is much harder to reverse the process.

I'm not sure if a cutting broach would be better for this application eg Bergeon 1896G, rather than the smoothing type Bergeon 1896H, maybe another member with more experience in this type of thing could provide us with some guidance?

[kaan]

Thanks for the feedback - there's NO WAY they could fit, I might've even bent a needle and tarnished a friction spring while trying

Afterwards, I had an extra needle, I've even sharpened that needle a bit and there was no way it was getting a grip

Indeed I'm leaning towards 1896G instead of H - as far as I've asked a friend who's training to be a watchmaker, a cutting broach was his suggestion as well

Let me know if there's a specific product that's better for the job

[oldhippy]

One thing you need to be careful with when making the seconds hand pipe larger is the pipe will go round with the broache, go very careful and don't try to force it and use lube to help the cut. 

[Endeavor]

You can also use a sewing needle. Grind the tip in the length (axial) sharp with a medium size (#200-#300) grit emery paper, so the scores in the needle tip will remove some material, and slowly start to open up. Keep checking your progress.

For example fine drills do snap off easy, rendering the seconds hand instantly useless.

Edited May 22, 2023 by Endeavor