how to tell titanium grade

peter r

peter r

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Jun 8, 2009
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is there an easy way to tes the grade of a titanium plate? i have a rather large piece. it was given to me as a gift and i dont know what grade it is.

also, if anyone can enlighten me on any grades besides 6al4v that are suitable for framelocks or linerlocks.

Thanks in advance!
Peter R
 
Reread question... link I posted is worthless for the question asked. Sorry!
 
If it is not marked...you are probably up a creek. Mechanical tests in a lab could probably get you there or if you could accurately weigh it, 6Al-4V weighs .160 pounds per cubic inch, 6-2-4-2 weighs .164 pounds per cubic inch and 6-2-4-6 weighs .168 pounds per cubic inch. The problem is there are other alloying that are in each weight group and it would be tough to weigh. Just make whatever you were going to make with it and test to see if it performs....it will be good practice at the least.
Jim
 
Short of provenance or a chemical test, you're probably stuck guessing. I think different Ti alloys respond differently to heat treatment. If you really need to know and have a hardness tester, you could devise some kind of experiment based on known data.

I think an end user would have a hard time noticing a difference. If you're worried about it being softer/weaker, you could always carbidize any contact points (like a lock face) - that would really make it hard to notice a difference. Just be upfront about it when you go to sell it and you'll be fine.
 
I believe that grade 2, Commercially pure is not as springy

May be mistaken on that.


But if in your testing it seems to work, then I'd give it a try.

I also believe that 6AL4V is the most common alloy


OP

Try asking the person who gave it to you.
 
it was given to me by a machinist who had a bunch of it sent to him by a client for testing. no label, and the client never got back to him. im going to take a piece of 6al4v and test the hardness and then compare to this stuff.

i have noticed that it gauls more than the stuff i usually use. well see.
 
Each grade anodizes a little differently.Take a known piece of 6al4v and anaodize it then anodize the unknown piece at the same voltage and compare.
 
You could also get 2-3 known samples and do a spark comparison test. If you tested CP2, 6Al4V, and 3Al2V you would get slightly different sparks and identify yours by matching the sparks.
 
Grade 2 and CP are weak, though they have the same elastic modulus as all Ti alloys. Only thing I can suggest is bend a piece in a vise and bend some steel of the same dimensions (note Bend not just flex). If it takes a lot more force to bend it might be 6-4 (about 130 ksi yield). Grade 2 is only about 50ksi, and mild steel is usually a minimum 50 ksi but could be 80ksi depending on composition and rolling. If it feels way hard to permanently bend then you may be looking at 6-4 STA or even a Beta alloy, yield strengths around spring tempered steel 175 -200 ksi.

Exact alloy will cost a chem analysis or maybe the above mentioned anodizing comparison with known samples, but the bottom line for building stuff out of it is: "strong or not?"

http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MTU021
 
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