Can I resize a titanium engagement ring?

No. Not the way you size a gold or platinum ring. Titanium is a different animal at the bench, and anyone who tells you otherwise is either trying to sell you something or has never actually tried to work the metal.

A traditional resize means cutting the shank, adding or removing metal, and soldering it back together. Gold and platinum solders flow at predictable temperatures and melt into the parent metal. Titanium doesn't do any of that. It oxidizes almost instantly when heated, and soldering it in open air produces a brittle mess, not a joint. To weld titanium properly you need an argon flood, a laser or TIG setup, and a filler rod that matches the alloy. Most retail jewelry shops don't have that equipment. I don't have it in my studio, and I've been at this for 22 years.

There is one partial exception worth knowing. If the ring is slightly too big, a bench jeweler can sometimes grind material from the inside of the band and bring it down a quarter-size, maybe a half-size. That works because you're removing metal, not joining it. If the ring is too small, there's no good way to add circumference. You can't stretch titanium on a mandrel the way you can a thin gold band. It hardens and snaps.

Last March a man named Marco came in with a titanium engagement band, size 9, needed a 10.5. The ring had been made for him by a shop out in Portland, and he'd worn it for a year before his finger changed. I told him the truth: a proper resize would cost more than the ring did new, and the result still wouldn't be invisible. The seam would show. The metal would be stressed. He ended up ordering a new band in the correct size and keeping the original as a travel ring. That's not a happy ending in the usual sense, but it's the honest one.

Which leads to the bigger point. Titanium is a fine material for a band if you understand what you're buying. It's light, hypoallergenic, nearly scratch-proof, and cheap. Most titanium engagement rings run $80 to $400. But the reason they're cheap is partly that they're made to specs, not sized to a finger after the fact. If your weight fluctuates, if you gain a full ring size, you replace the ring. That's the tradeoff, and jewelers are bad about explaining it up front because explaining it costs a sale.

So if you're holding a titanium ring that doesn't fit and you're hoping for a $60 resize, I'd put that thought down. Replace it. Size the replacement correctly the first time, and if the ring matters to you emotionally, keep the original on a chain or in a box. It did its job.