how can you tell if it's really titanium?

[djinnform]

I found an Automag Dye titanium barrel on e-bay for $120 bucks. How do I know this isn't just steel or aluminum. Does anyone remember what they made or looked like? I've never seen a 2 piece like this? Thank you.

link:

http://i.ebayimg.com/t/Dye-barrel-titanium-Automag-14inch-2-piece-/00/s/MTE5NVgxNjAw/z/emEAAOxyldpR-ZX1/$T2eC16RHJIkFHRy1GbbZBR-Z(044NQ~~60_57.JPG

[Ando]

The barrel will have a TI stamped on it if its titanium.

[sniper42]

You should be able to feel just by weight to tell if it is stainless. Only way I know how to tell if it is titanium is if you take it to a belt sander, titanium will throw sparks where aluminum will not. I realise you probably don't want to take your barrel to a sander though.

[Frizzle Fry]

You could scratch it with steel (a bastard file or something) on the haft and see if it sparks. That way you wouldn't effect functionality and the scratch would be hidden when the barrel was installed on a marker.

[sniper42]

I don't think scratching it with a file would cause it to spark. For the same reason when you file steel it doesn't spark but when you take it to a sander it does. It needs to be a rapid material removal I think to get it to spark. You wouldn't necessarily have to sand a bunch of it. If you do the same thing Frizzle Fry recommends but with a belt sander that could work. It would be a small cosmetic mark hidden when the barrel is installed.

[nak81783]

OP, do you have this barrel in hand or no?

If no, it should have "Ti" or "TITANIUM" stamped on it. Have the seller send you a picture of the stamp. Obviously, if you have the barrel in hand, you can simply look for the stamp as well.

If there is no stamp, there are a couple of non-destructive tests that I know about (I'm sure there are others) that can be done at a metallurgical lab, but I don't know how much a lab would charge for the testing. Many manufacturing/machine shops have these tests in-house to verify incoming material and outgoing product. If you have family/friends in such lines of work, you might want to ask if they have the equipment and could run the test for you.

1. XRF - the ones I've used are portable handheld gun-looking devices. Simply scan the metal, and it will A. give you a breakdown of the elemental composition which you can compare to the specification (e.g. an AMS spec, I'm assuming some form of Titanium alloy was used and not just pure Titanium), or B. if all the elemental compositions are within the ranges of a known material/alloy that has been pre-loaded into the XRF's software, it will tell you what it is. Obviously, you're looking for a high percentage of Titanium in the results...

2. Portable FTIR - I've only used this once, and it was on composites. But I think it works for metals too. After taking a scan, it outputs a graph of transmittance vs wavelength. Basically, the more of a certain wavelength is absorbed, it's an indicator it has that unique wavelength-absorbing chemical in it's structure. You compare that output graph to a graph of a known standard. If the fingerprints (graphs) match, that's your material. Make sure you ask for portable FTIR (the non-destructive version). There is also through-transmission IR method that requires a sample (destructive testing) from the parent material.

[athomas]

If you had it in hand, weight would be the best indicator. Measure the displacement in water. Measure the weight. Determine the density of the material.

However, it is more difficult to determine by looking at it online through an auction. It has to be stamped or verified by some other means to determine whether it is stainless, aluminum, or titanium.