unknown plate

[thepuma]

in my work as a welder for a small contractor i am often demolishing or simply removing old and sometimes hard to identify metals. a thick(1-3/16 inch) plate of non ferrous-non magnetic metal bears the code"24s-t4 00 A-355..."It is at least as old as the simulated nuclear reactor it was built to support circa 1960.Can someone tell me its allows and weldable properties?

 

[Gaz]

Try posting this question over at the "Material Engineers" or "Alloy Engineering" forums, they might be able to help.
Good luck
Gary

 

[delta769]

That sounds like the old designations for aluminum alloys. The modern designation would be 2024-T4. The A-250 type number would be a procurement spec. Check stinet.dtic.mil and search for QQ-A-250 and its slash sheets for specific forms and alloys. QQ-A-250 is the current Fed Std for general aluminum requirements, likely also changed numbering since that item was built.