Hi,

Would any of the Waltham experts on this forum know or have access to the roller jewel size required for a M1908 #17418312 16S OF?? I have the roller table but the jewel was gone when I bought the watch.

Regards, Phil

The jewel for one of my M1908's was a 0.46 mm but would accept a 0.465 mm as well.

You can measure the slot of the pallet fork and subtract .02 mm and you'll have the size necessary.

What range Waltham made their roller jewels for these watches is unknown by me.

Tim,

Thanks for your quick reply. I just measured the slot in pallet & mine measures 0.50mm. So I guess a 48 will be OK.

I would have thought this would have been a standard dimmension throughout a particular model in a given era?

Regards, Phil

I guess that there was plenty of variation in the width of the fork opening due to manufacturing wear and tear on tooling. If they were producing thousands or several thousand a day, I imagine that a pallet fork opening might vary quite a bit in the same run for the same model. Plus, the possibility of human error...

Also, wear on the fork from millions (perhaps billions) of "ticks" since it was manufactured.

Still, if you think about it, the variation is not that great, but with such small parts it can make a big difference - just like in a roller jewel fitting the pallet just right for smooth operation.