ASTM E527-07
(Practice)Standard Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
Standard Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
SIGNIFICANCE AND USE
The UNS provides a means of correlating many nationally used numbering systems currently administered by societies, trade associations, and individual users and producers of metals and alloys, thereby avoiding confusion caused by use of more than one identification number for the same material; and by the opposite situation of having the same number assigned to two or more entirely different materials. It also provides the uniformity necessary for efficient indexing, record keeping, data storage and retrieval, and cross referencing.
A UNS number is not in itself a specification, since it establishes no requirements for form, condition, quality, etc. It is a unified identification of metals and alloys for which controlling limits have been established in specifications published elsewhere.
Note 5—Organizations that issue specifications should report to appropriate UNS number-assigning offices (3.1.2) any specification changes that affect descriptions shown in published UNS listings.
SCOPE
1.1 This practice (Note 1) covers a unified numbering system (UNS) for metals and alloys that have a "commercial standing" (see Note 2), and covers the procedure by which such numbers are assigned. Section 2 describes the system of alphanumeric designations or "numbers" established for each family of metals and alloys. Section outlines the organization established for administering the system. Section 3 describes the procedure for requesting number assignment to metals and alloys for which UNS numbers have not previously been assigned.Note 1
UNS designations are not to be used for metals and alloys that are not registered under the system described herein, or for any metal or alloy whose composition differs from those registered. Note 2
The terms "commercial standing," "production usage," and other similar terms are intended to apply to metals and alloys in active commercial production and use, although the actual amount of such use will depend, among other things, upon the type of metals and alloys involved and their application.
The various standardizing organizations involved with the individual industries apply their own established criteria to define the status of a metal or alloy in terms of when a UNS designation number will be assigned. For instance, ASTM Committee A01 requires details of heat analysis, mechanical properties, and processing requirements for addition of a new grade or alloy to its specifications. The Copper Development Association requires that the material be "in commercial use (without tonnage limits);" the Aluminum Association requires that the alloy be "offered for sale (not necessarily in commercial use);" the SAE Aerospace Materials Division calls for "repetitive procurement by at least two users."
Thus, while no universal definition for usage criteria is established, the UNS numbers are intended to identify metals and alloys that are generally in regular production and use. A UNS number will not ordinarily be issued for a material that has just been conceived or that is still in only experimental trial.
General Information
Standards Content (Sample)
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Designation:E527 −07
StandardPractice for
Numbering Metals and Alloys in the Unified Numbering
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System (UNS)
This standard is issued under the fixed designation E527; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
Materials Division calls for “repetitive procurement by at least two users.”
1. Scope*
Thus, while no universal definition for usage criteria is established, the
1.1 This practice (Note 1) covers a unified numbering
UNS numbers are intended to identify metals and alloys that are generally
system (UNS) for metals and alloys that have a “commercial in regular production and use.AUNS number will not ordinarily be issued
for a material that has just been conceived or that is still in only
standing” (see Note 2), and covers the procedure by which
experimental trial.
such numbers are assigned. Section 2 describes the system of
alphanumeric designations or “numbers” established for each
2. Description of Numbers (or Codes) Established for
family of metals and alloys. Section 3 outlines the organization
Metals and Alloys
established for administering the system. Section 5 describes
2.1 The UNS establishes 18 series of numbers for metals
the procedure for requesting number assignment to metals and
and alloys, as shown in Table 1. Each UNS number consists of
alloys for which UNS numbers have not previously been
a single letter-prefix followed by five digits. In most cases the
assigned.
letter is suggestive of the family of metals identified; for
NOTE 1—UNS designations are not to be used for metals and alloys that
example, A for aluminum, P for precious metals, and S for
are not registered under the system described herein, or for any metal or
stainless steels.
alloy whose composition differs from those registered.
NOTE 2—The terms “commercial standing,” “production usage,” and
2.2 Whereas some of the digits in certain UNS number
other similar terms are intended to apply to metals and alloys in active
groups have special assigned meaning, each series is indepen-
commercial production and use, although the actual amount of such use
dent of the others in such significance; this practice permits
will depend, among other things, upon the type of metals and alloys
greater flexibility and avoids complicated and lengthy UNS
involved and their application.
numbers.
The various standardizing organizations involved with the individual
industries apply their own established criteria to define the status of a
NOTE 3—This arrangement of alphanumeric six-character numbers is a
metal or alloy in terms of when a UNS designation number will be
compromise between the thinking that identification numbers should
assigned. For instance, ASTM Committee A01 requires details of heat
indicate many characteristics of the material, and the belief that numbers
analysis, mechanical properties, and processing requirements for addition
should be short and uncomplicated to define only the chemical composi-
of a new grade or alloy to its specifications. The Copper Development
tion and leaving the other properties to the specifications involved.
Association requires that the material be “in commercial use (without
tonnage limits);” the Aluminum Association requires that the alloy be
2.3 Wherever feasible, identification “numbers” from pre-
“offered for sale (not necessarily in commercial use);” the SAEAerospace
vious systems are incorporated into the UNS numbers. For
example: carbon steel, originally identified by “American Iron
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andSteelInstitute(AISI)1020,”iscoveredby“UNSG10200,”
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
and free cutting brass, presently identified by “Copper Devel-
A01.91 on Editorial.
opment Association (CDA) C36000,” is covered by
Current edition approved Sept. 1, 2007. Published October 2007. Originally
“UNS C36000.” Table 2 shows the secondary division of some
approved in 1974. Last previous edition approved in 2003 as E527–83 (2003). DOI:
10.1520/E0527-07. primary series of numbers.
*A Summary of Changes section appears at the end of this standard
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E527−07
TABLE 1 Primary Series of Numbers
Nonferrous Metals and Alloys
A00001–A99999 aluminum and aluminum alloys
C00001–C99999 copper and copper alloys
E00001–E99999 rare earth and rare earth-like metals and al
...
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