Best solder for a stainless steel watch case?

I have a personal project where I need to solder a stainless steel ring (it’s a 2mm thick rings that goes on top of the watch case that will hold the crystal) onto the the stainless steel mid-case.

I have the “case neck ring” to a nice pressure fit size so all I need to do at this point is choose a solder that I should solder them with. I plan on using the method of locking the entire case and ring in position using investment and clay so that nothing moves.

I think ideally, one would have it laser welded. However, I can’t afford to have someone do this (even if I found a jeweler that has stainless laser welding materials). My guess is that jewelers that have laser welding machines don’t ever stock stainless materials, am I correct? So they would just refuse me.

I have soldered stainless steel before and know about using the black flux that is required. But I’m not sure what is the best solder for this application. I’d like it to be strong and corrosion resistant as this is for a water proof watch build.

Does anyone have recommendations for solder? I think a choice would be a type of Silver Solder but how do I know which ones are more resistant to salt water or chlorine exposure?


I can’t speak to the solder, but to the laser welding. As a jeweler with both laser and fusion welders, we stock the material. If it’s not stocked, it’s a matter of a day to get the fill wire. As for cost, closing a jump ring is minimal and if you’re willing to do the clean-up, the price would be negligible.

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Thanks, maybe I should ask around then. Laser welding would be ideal because any type of solder will be more prone to corrosion. Thanks for the advice.

If I can’t find a laser welding place, I think I would use this stuff. Airgas - RAD64001776 - RADNOR™ 3/64" Stay Brite® Rosin Core Silver Solder And Wire Kit 0.100 lb With 1/2 Ounce Stay Clean® Liquid Soldering Flux (Prices are subject to change without notice due to raw materials cost volatility)

I think that most of his who laser weld stock stainless steel wire. Stainless lasers rather well.

As for soldering, I just pulled up this older Orchid thread:

I would suggest that the higher the karat gold solder you use, the less salt water and chlorine would be an issue. Gold solder would be my choice over silver for this application for that reason.

Trial run on scraps first?
Good luck.

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Maybe I misread the question, but I was picturing soldering a stainless crystal bezel onto a stainless watch case, not welding a jump ring closed.

THAT last is dead easy with the laser, while laser welding a crystal bezel would be a much more demanding job.

You all were right. The very first jeweler I called who laser welds does indeed carry the stainless material and he is very open to checking out my job. Thanks. He is convinced though, that the amount of cleanup required after laser welding it enough to be water proof will be huge compared to just properly silver soldering it.

Ive nothing to add beyond what is suggested, would love to see the work when it is ready to be shown

If it is hard soldering (like silver soldering) you might want to look at some of the solders offered by gun smith companies. They are made specifically for such things as soldering sights onto barrles and as solders match the color of stainless steel very well.

Thanks for the idea. I’ll look into it. Appreciate it.