Aluminium Specifications

[Stressmerchant]

Hi all, first time poster. Apologies if this topic is a repeat.

I do a lot of work with DC-3 / C47 aircraft. The Structural Repair Manual (SRM) and manufacturing drawings specify alumimium (or aluminum for my American friends ) grades such as 24ST. The modern equivalent of 24 is 2024, with the ST being replaced with a suffix such as -T3 or -T4.

I have my own informal table of equivalents, drawn up by comparison with properties. However, at some stage there must have been a technical document advising users of the equivalence between the specification nomenclatures. Does anyone know of such a document, probably a TO or something similar?

[FLYBOYJ]

Advisory Circular AC.43.13 and the "Standard Aircraft Handbook." I think both books provide equivalents between the old designators, it is pretty straight forward. What exactly are you looking for?

[Stressmerchant]

Must have the wrong editions of those references, I don't see any comparison table.

As an example, what are the official modern equivalents for "24ST, Bar, to 4 in, cross gr" and "24ST Extruded shapes"?

[FLYBOYJ]

Originally Posted by Stressmerchant

Must have the wrong editions of those references, I don't see any comparison table.

As an example, what are the official modern equivalents for "24ST, Bar, to 4 in, cross gr" and "24ST Extruded shapes"?

24ST should be 2024 - as far as the temper (T3, T4) will depend on useage. Does this help?

Aluminum Tempers - Engineers Edge

Also see the attached document.

Hope this helps.

[Stressmerchant]

Thanks for that. I use the Mil-Hdbk 5 or MMPDS to compare figures, but it occurs to be that at some point the US military would have issued a TO or similar document advising technical personnel of the equivalents between the different grades and treatments.

I guess they just handled it the same way we are doing now