Got an inexpensive titanium ring the other day for less than 10 dollars off ebay. I thought I measured my ring size correctly but it’s too big (size 15) and I’ll probably use it as a key ring fob. I m curious if there a non-destructive way to test that it’s actually titanium. It says “titanium” inside the ring but who knows. It’s seems lighter than steel, almost aluminum like but not quite that light, and it has a shiny surface like stainless steel.
If you expect the ring to be 100% titanium, you might be able to do an accurate measurement of its volume by dropping it in a graduated cylinder and seeing how much water it displaces. Then you could figure out its density and see if it compares to the book number for titanium.
If it’s harder than aluminum and lighter than steel, what else is it likely to be?
Really cheap steel?
Eureka!
You’re running naked through the thread, aren’t you?
With a magnet, you can confirm whether or not it’s iron or steel. Or that it has iron or steel in it. Or maybe cobalt. Titanium’s not particularly magnetic.
CMC fnord!
Stainless steel is not magnetic either.
I have two stainless knives stuck to the magnetic rack in my kitchen. I’d call them “stainless steel”; is there a different type?
Interesting, the stainless steel in familiar with is nonmagnetic. There’s probably specific heat treatments that get the magnetic qualities back.
As tellyworth has already noted, some ‘stainless steel’ is indeed, ‘magnetic’.
There are many different types (grades?) of stainless steel and some will not attract a magnet.
The ‘magnet test’ is not an accurate method of determining whether or not something is ‘stainless steel’. There are some (albeit, they’re not all that prevalent) scrap metal recyclers that will attempt to scam one into thinking that the scrap in question is not stainless steel, simply because a magnet won’t stick to it.
The more honest and reliable recyclers will invariably use a more accurate method to determine what type of metal you have brought to them.
I speak from experience, I once found a ‘billet’ of metal on the side of the road, it was about the size of a 1 gallon paint can, yet weighed an incredible amount. (I couldn’t lift it, I had to rig up a ramp in order to roll it up into the back of my truck.)
It ‘looked’ like stainless steel, yet a magnet would stick to it. The first scrap yard I took it to did the ‘magnet test’ and offered me $1.50/lb, telling me it wasn’t stainless steel. :dubious:
Not happy with this, I took it to a more reputable recycler. They used a tester that resembled a ‘gun’, it had two electrode/prongs that they touched to the object which gave a readout on the exact composition (isn’t technology wonderful?) of the metal.
Long story, short…
I ended up getting almost triple the amount, that I was originally offered. 
Moral… Get more than one ‘opinion’, and if possible have it tested electronically. I don’t know if the tester that was used in my case would work for you, but I don’t see why not.
It turned out that it was stainless steel, it was some type of special ‘grade’ that a magnet would stick to.
Step right up and watch a man’s opinion change before your very eyes!
I didn’t want to threadshit but the OP paid ten dollar American for a titanium ring and now wants to make sure it’s really titanium? Who cares? It was ten bucks and a decent assay (assuming he doesn’t have the precision tools to play Archimedes with it) will cost more. Enjoy the ring for what it is, which is costume or art jewelry made out of a base metal. Drop it on concrete and if it shatters you didn’t want to wear tungsten carbide anyway. And if it’s only stainless, scratches add character. But whatever it is it ain’t precious or even noble.
Now, don’t get me wrong. Titanium can be beautiful, especially that iridescent effect you can get with it. I still have an inch square sheet of titanium that had been hit with a blowtorch; it was the first time I saw the stuff (~1965) and I was enchanted and immediately saw potential for art jewelry. The deep colors can be butch, though Sig Sauer is using it to dress up its latest girl guns. 
And manufacturers use magnetron ionization to deposit it on quartz crystals, making spectacular cocktail rings that would set off whatever little, black dress a lady would like. And that Timoku faux woodgrain is wicked cool. Y’know, if a guy happened to figure out the ancient process (I’m thinking it involves a resist and heat or acid) and had some cheap, plain bands he could have some fun and maybe make some money, especially if his daughter is going to rent a shelf in an artsy jewelry shoppe.
Where did you say you got that ring? 
Ebay- My point was just pure scientific curiosity in that it was so cheap and being too larger had no further utility, but I’d prefer not to use a Dremel grinding wheel on it to test the spark color composition.
As pointed out Ti will go all sorts of colours if heated with a blow torch and retain the colours which most metals wont. Try to stop when its red or peacock blue as it goes sort of muddy straw right after, and its a swine to get back to plain metal!
Made that mistake when experimenting with hand beating Ti !
How would this determine the material? If you took 3 rings, all the exact same size, one titanium, one steel and one aluminum, dropped them in water, would they not displace the exact same amount of water?
Now that I think about that for a second, IMHO, you are absolutely correct. 
I’m sure there will be someone along later that will know for sure, though.
Damn, that sure is a purty pistol!
Yes. But the rings themselves weigh different amounts, so you measure the density.
(With a more accurate scale than most Dopers have handy)
Probably not worth it, but would the OP settle for a semi-destructive test? That is, a test which would destroy it if it’s not titanium, but leave real titanium unharmed?