Grade 2 Titanium

[nctexan22]

I've seen differing abbreviations for Grade 2 Titanium on manufacturer and supplier websites. Some call out Grade 2 as CP-2, while others, CP-3. Some define Grade 3 as CP-2. Which is it? ASTM B 348-08a does not define nor distinguish any abbreviations for Titanium.

 

[TVP]

The CP designation comes from MIL-T-9046 and its replacement, SAE-AMS-T-9046. You can review the requirements and compare against the ASTM grades by downloading the .pdf file of MIL-T-9046 Revision J here:

http://assist.daps.dla.mil/quicksearch/basic_profile.cfm?ident_number=7475

 

[nctexan22]

Thanks for the info TVP, I think I've got it. For example,
MIL-T-9046J's classification of CP-2 requires a minimum yield strength of 55 ksi, which would correspond to ASTM's Grade 3 min. yield. I appreciate it.

 

[EdStainless]

With the commercially pure grades you need to watch. Just like you have found there is also a lot of gaming going on with strength levels.
The Japanese usually make two strength levels that roughly split the line between grades 1-2 and grade 3. So when you get grade 2 it is right at the bottom end of the range.
In the US they tend to the other way, they make grade 1 and a grade 2-3 split. So the US material for grades 2 tends to right at the upper end of the range.

Yes, it is good to ask questions.
In order simplify this you could use the UNS numbers for the alloys.
R50250 is ASMT grade 1
R50400 is ASTM grade 2
R50550 is ASTM grade 3

The ASTM and MIL grades use the same yield strength ranges, BUT THEY HAVE DIFFERENT CHEMISTRY LIMITS. It is possible (and likely) that an alloy would meet both, but it may not.

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