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How To Tell If It's Really Titanium

Posted by Zonk on from the hold-your-credit-card-to-a-grinder dept.

With the growing popularity of titanium, some disreputable merchandisers are passing off other materials as the more expensive metal. Popular Science looks at a surefire way to prove what that credit card/crowbar/ring is really made of. "Hold any genuine titanium metal object to a grinding wheel (even a little grindstone on a Dremel tool will do), and it gives off a shower of brilliant white sparks unlike any softer common metal. The sparks are tiny pieces of cut titanium--the friction of the grinder heats them till they burn white-hot. Hold a grindstone to the shackle of a "titanium" padlock from Master Lock, however, and you'll instead see the telltale fine, long, yellow sparks of high-carbon steel."

4 of 280 comments (clear)

  1. Re:color, texture, weight by Alaria+Phrozen · · Score: 5, Informative

    Wtf is with these fake links? Do you get money or something for that stupid city?

  2. A few simple ones by BlueParrot · · Score: 5, Informative

    a: Titanium is not ferromagnetic, and hence it is not attracted by magnets as strongly as iron is ( the difference in force should be orders of magnitude ).
    b: Titanium's density is 4.5g/cm^3 , iron is 7.8g/cm^3
    c: Titanium is corrosion resistant to dillute sulfuric and hydrochloric acid, iron is not.

  3. Re:a magnet? by LynnwoodRooster · · Score: 5, Informative
    Nope. Get above 0.15% carbon or so and you lose almost all the magnetic properties of iron. It's one reason that loudspeakers are made with low carbon steel (usually 1006, 1008, or 1010 grade) since you get too much carbon and the flux no longer flows well, meaning you need a LOT more magnet and a higher grade magnet to get the same flux in the gap.

    And yes, I am a loudspeaker engineer... ;)

    MERRY CHRISTMAS!

    --
    Browsing at +1 - no ACs, I ignore their posts. So refreshing!
  4. Re:is there a better way? by necro81 · · Score: 5, Informative

    How much are you paying for that service? For $30,000-40,000, you can buy a handheld x-ray fluorescence analyzer. These things got started in testing for lead paint, and now get used to test and check for lots of things - including alloy composition verification. An XRF shines x-rays of a known energy at the test sample, then detects and analyzes the spectrum that is reflected back. Each element has a characteristic x-ray emission spectrum based on the energy of electrons dropping into lower shells. In 10-20 seconds, you can get a really good breakdown of the elements in the test sample.