Use have aluminum numbers as reference, but I'll try to give you full representation.

From The Science and Engineering of Materials by Donald R. Askeland

STEEL
AISI steel designations have 4 or 5 digits.  The first two numbers refer to the major alloying elements present; the last two or three refer to the average percent carbon.  For example, a 1020 steel is a plain-carbon (10XX) with about .20% carbon (XX20).  4340 steel is an alloy with about .40% carbon (XX40) and other alloying elements (43XX).  I do not have a good reference at this time that relates the first two digits with any specific alloy element and percentage of.

ALUMINUM
Aluminum alloys can be divided into two major groups: wrought and casting alloys.  These groups can be divided into two sub-groups: heat-treatable and nonheat-treatable alloys.  The first number of the designation specifies the principle alloying elements.  The remaining numbers refer to the specific composition.  The temper designation (T or H) refers to heat-Treated or strain-Hardened.  Other designations include annealed (O), solution-treated (W), or as-fabricated (F).  The numbers following the T or H refer to the type of heat treatment or amount of strain hardening.

Wrought Al Alloys:
1xxx Commercially pure (>99% Al)
2xxx Al-Cu and Al-Cu-Li
3xxx Al-Mn
4xxx Al-Si and Al-Mg-Si
5xxx Al-Mg
6xxx Al-Mg-Si
7xxx Al-Mg-Zn
8xxx Al-Li, Sn, Zr, or B
Casting Al Alloys:
1xx Commercially pure Al
2xx Al-Cu
3xx Al-Si-Cu or Al-Mg-Si
4xx Al-Si
5xx Al-Mg
7xx Al-Mg-Zn
8xx Al-Sn

I think I'll create an FAQ about this.  Thanks for making me look this up again.  It has been a while since I refreshed my memory on this subject.

--Scott

An FAQ would be a great service. Don't neglect to show how all the industry and company nomenclature is evolving to the UNS system which will encompass all national norms and alloy families.

Take a look at this link for a good explination
on steel  http://www.survivalistbooks.com/faq/metalfaq.htm