What is the material designated by the spec QQ-A-250/11 7075?

Question

IS it bare aluminum or clad aluminum?

Answer 1

QQ-A-250/11 refers to alumninum strip, coil, or plate made to 6061 chemical composition.

QQ-A-250/12 refers to the same materials, except with the 7075 chemical composition.

Which do you really need to know about?

Answer 2

As CanTexan noted, QQ-A-250/11 is for 6061, and /12 is for 7075.  Neither are alclad.  QQ-A-250/13 is 7075 alclad, and /18 is alclad one side.  For pretty obvious reasons, 6061 is not offered commercially as an alclad product.  (Really, what's the point?  It's corrosion resistance is fine as is.)

Go to http://assist.daps.dla.mil/quicksearch/ and type '250' into the number box, and you'll get the list of Federal specifications in the QQ-A-250 family.