European standards for designation of aluminum and aluminum alloys,
which is submitted to Technical Committee CEN / TC 132 “Aluminum and Aluminum Alloys”,
have two basic designation systems: chemical symbol based designation system and numerical
designation system. Chemical symbol based designation system is mainly the same for
wrought products and castings while numerical system differs for wrought and casting products...
European standards for designation of aluminum and aluminum alloys, which
is submitted to Technical Committee CEN / TC 132 "Aluminum and Aluminum
Alloys", have two basic designation systems: chemical symbol based
designation system and numerical designation system.
Chemical symbol based designation system is mainly the same for wrought
products and castings while numerical system differs for wrought and
casting products.
European Standard (EN) and International Aluminum Association (UNS) for
wrought products use the same numerical designations with the prefix EN
or AW.
The standard Aluminum and aluminum alloys - Designation of alloyed
aluminum ingots for remelting, master alloys and castings - Part 1:
Numerical designation system (EN 1780 - 1:1999) is a revision of
Standard EN 1780 - 1:1996. The difference to the former version is
that unalloyed aluminum is removed from the scope and provisions dealing
with unalloyed are deleted.
This standard is a part of EN 1780 titled "Aluminum and aluminum
alloys - Designation of alloyed aluminum ingots for remelting, master
alloys and castings", which has three parts:
Part 1: Numerical designation system
Part 2: Chemical symbol based designation system
Part 3: Writing rules for chemical compositions
The numerical designation system for aluminum and aluminum alloys and
master alloys consists of prefix letters and five-figure designation.
Basis of codification
The designation is constituted successively by:
- prefix EN (European Standard) followed by a blank space,
- letter A representing aluminum,
- letter representing the form of the product,
- letter B representing alloyed aluminum ingots for remelting, C representing castings, and M representing master alloys,
- a hyphen,
- five figures representing the alloy composition limits.
The prefix letters of alloys for aerospace applications are different from
those above and are specified in EN 2032-1.
Aluminum alloys, ingot and castings have the same numerical designation.
The first of the five figures in the designation indicates the major
alloying elements as follows:
- copper: 2XXXX,
- silicon: 4XXXX,
- magnesium: 5XXXX,
- zinc: 7XXXX.
The second of the five figures in the designation indicates the alloy
group:
21XXX : AlCu,
41XXX : AlSiMgTi,
42XXX : AlSi7Mg,
43XXX : AlSi10Mg,
44XXX : AlSi,
45XXX : AlSi5Cu,
46XXX : AlSi9Cu,
47XXX : AlSi(Cu),
48XXX : AlSiCuNiMg,
51XXX : AlMg,
71XXX : AlZnMg.
The third figure is arbitrary. Indicates various alloys inside the
given group. Differences in chemical compositions are minimal.
The forth figure is generally 0.
The fifth figure is always 0 except for alloys for aerospace
applications.
Master alloys
The first of the five figures in the designation system is the
number 9.
The second and third figures represent the atomic number of the
main element.
The last two figures are chronological numbers, but for the fifth figure:
- an even figure is reserved for a master alloy with low level of
impurities.
- an odd figure is reserved for a master alloy with high level of
impurities.
CEN (European Committee for Standardization) members are bound to comply
with the CEN/CENELEC Internal regulations, which stipulate the conditions
for giving the European Standard the status of a national standard without
any alteration.
This European Standard incorporates by dated or undated reference,
provisions from other publications. These normative references are cited
at the appropriate places in the text. For dated references, subsequent
amendments to or revisions of any of these publications apply to this
European Standard only when incorporated in it by amendment or revision.
For undated references the latest edition of the publication referred to
applies.