ASTM B951-11(2018)

Standard Practice for Codification of Unalloyed Magnesium and Magnesium-Alloys, Cast and Wrought

ABSTRACT
This practice provides a system for the codification of unalloyed magnesium and magnesium alloys in the cast and wrought forms. Code designations shall be based on their chemical composition limits. For alloys, designations shall consist of not more than two letters representing the alloying elements specified in the greatest amount, followed by the respective percentages and a serial letter. The letters that represent the alloying elements are: A for aluminum; C for copper; E for rare earths; J for strontium; K for zirconium; L for lithium; M for manganese; Q for silver; S for silicon; T for tin; V for gadolinium; W for yttrium; and Z for zinc. For unalloyed metals, designations shall consist of the specified minimum purity, followed by a serial letter. For both cases, the full name of the base metal precedes the designation, but is omitted for brevity when the base metal being referred to is obvious.
SCOPE
1.1 This practice provides a system for designating unalloyed magnesium and magnesium-alloys that have been used commercially since 1952, and thus is intended to be the registration source for unalloyed magnesium and magnesium-alloys. A record of designations along with the established compositions is given in Table 2.  
1.2 The equivalent Unified Numbering System (UNS) alloy designations shown in the appendixes are in accordance with Practice E527.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2018
• ICS: 77.150.20 - Magnesium products
• Technical Committee: B07 - Light Metals and Alloys
• Drafting Committee: B07.04 - Magnesium Alloy Cast and Wrought Products

Relations

• Replaces: ASTM B951-11 - Standard Practice for Codification of Unalloyed Magnesium and Magnesium-Alloys, Cast and Wrought
• Effective Date: 01-May-2018
• Refers: ASTM B843-18 - Standard Specification for Magnesium Alloy Anodes for Cathodic Protection
• Effective Date: 01-May-2018
• Refers: ASTM B92/B92M-17 - Standard Specification for Unalloyed Magnesium Ingot and Stick For Remelting
• Effective Date: 01-May-2017
• Refers: ASTM B91-17 - Standard Specification for Magnesium-Alloy Forgings
• Effective Date: 01-May-2017
• Refers: ASTM B90/B90M-13 - Standard Specification for Magnesium-Alloy Sheet and Plate
• Effective Date: 01-Nov-2013
• Refers: ASTM B94-13 - Standard Specification for Magnesium-Alloy Die Castings
• Effective Date: 01-May-2013
• Refers: ASTM B90/B90M-12 - Standard Specification for Magnesium-Alloy Sheet and Plate
• Effective Date: 01-Nov-2012
• Refers: ASTM B199-12 - Standard Specification for Magnesium-Alloy Permanent Mold Castings
• Effective Date: 01-Nov-2012
• Refers: ASTM B91-12 - Standard Specification for Magnesium-Alloy  Forgings
• Effective Date: 01-Nov-2012
• Refers: ASTM B107/B107M-12 - Standard Specification for Magnesium-Alloy Extruded Bars, Rods, Profiles, Tubes, and Wire
• Effective Date: 01-Nov-2012
• Refers: ASTM B92/B92M-11 - Standard Specification for Unalloyed Magnesium Ingot and Stick For Remelting
• Effective Date: 01-May-2011
• Refers: ASTM B80-09 - Standard Specification for Magnesium-Alloy Sand Castings
• Effective Date: 07-Dec-2009
• Refers: ASTM B93/B93M-09 - Standard Specification for Magnesium Alloys in Ingot Form for Sand Castings, Permanent Mold Castings, and Die Castings
• Effective Date: 07-Dec-2009
• Refers: ASTM B403-07 - Standard Specification for Magnesium-Alloy Investment Castings
• Effective Date: 01-Jun-2007
• Refers: ASTM B90/B90M-07 - Standard Specification for Magnesium-Alloy Sheet and Plate
• Effective Date: 01-Jun-2007

Overview

ASTM B951-11(2018) is an international ASTM standard that establishes a systematic practice for the codification of unalloyed magnesium and magnesium alloys, both cast and wrought. The codification system outlined in this standard enables uniform and clear identification of magnesium materials based on their chemical composition limits. This standard, developed in accordance with globally recognized principles for standardization, is critical for material traceability, procurement, and quality assurance in industries where magnesium alloys are widely used.

Key Topics

• Codification System: Designations for magnesium alloys are based on their chemical composition. For alloys, codes use up to two letters representing the principal alloying elements, numerical values for alloying element percentages, and a serial letter for differentiation.
  • Example: AZ91A designates an alloy with aluminum (A) and zinc (Z) as main alloying elements, approximately 9% Al and 1% Zn, serial letter A.
• Alloy Letter Codes: The standard assigns letters to common alloying elements:
  • A - Aluminum
  • C - Copper
  • E - Rare Earths
  • J - Strontium
  • K - Zirconium
  • L - Lithium
  • M - Manganese
  • Q - Silver
  • S - Silicon
  • T - Tin
  • V - Gadolinium
  • W - Yttrium
  • Z - Zinc
• Unalloyed Magnesium Codes: Designations consist of the minimum purity percentage without the decimal point, plus a serial letter (e.g., 9995A for 99.95% purity magnesium).
• Governance: Assignment, revision, and cancellation of designations are managed by ASTM Committee B07.04 on Magnesium Alloy Cast and Wrought Products.

Applications

The codification system provided in ASTM B951 is essential for:

• Material Selection: Ensures end-users, manufacturers, and suppliers can clearly identify and specify magnesium and magnesium alloy materials according to industry-accepted codes.
• Procurement: Assists purchasing departments in specifying magnesium materials accurately for industrial, aerospace, automotive, and electronics applications.
• Traceability: Supports quality control by providing a standardized method for recording and communicating material composition, traceable to a registration source.
• Compliance: Facilitates adherence to industry and international regulations regarding magnesium alloys, enhancing cross-border trade and production.
• Interchangeability: Enables the use of equivalent Unified Numbering System (UNS) designations, supporting substitution and equivalency in global supply chains.

Related Standards

Several ASTM standards are closely related to B951 and referenced within its scope, including:

• ASTM B80: Specification for Magnesium-Alloy Sand Castings
• ASTM B90/B90M: Specification for Magnesium-Alloy Sheet and Plate
• ASTM B91: Specification for Magnesium-Alloy Forgings
• ASTM B92/B92M: Specification for Unalloyed Magnesium Ingot and Stick for Remelting
• ASTM B94: Specification for Magnesium-Alloy Die Castings
• ASTM B107/B107M: Specification for Magnesium-Alloy Extruded Bars, Rods, Profiles, Tubes, and Wire
• ASTM E527: Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)

Practical Value

Adhering to ASTM B951 ensures uniformity and clarity when specifying, ordering, and certifying unalloyed magnesium and magnesium alloys. The standard reduces risk of material errors, improves communication across the supply chain, and promotes the use of magnesium as a lightweight material in high-performance and commercial applications. Correct codification supports innovation, quality control, and international trade for manufacturers and users of magnesium-based materials.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:B951 −11 (Reapproved 2018)
Standard Practice for
Codification of Unalloyed Magnesium and Magnesium-
Alloys, Cast and Wrought
This standard is issued under the fixed designation B951; 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.
1. Scope* B107/B107M Specification for Magnesium-Alloy Extruded
Bars, Rods, Profiles, Tubes, and Wire
1.1 This practice provides a system for designating unal-
B199 Specification for Magnesium-Alloy Permanent Mold
loyed magnesium and magnesium-alloys that have been used
Castings
commercially since 1952, and thus is intended to be the
B403 Specification for Magnesium-Alloy Investment Cast-
registration source for unalloyed magnesium and magnesium-
ings
alloys. A record of designations along with the established
B843 Specification for Magnesium Alloy Anodes for Ca-
compositions is given in Table 2.
thodic Protection
1.2 The equivalent Unified Numbering System (UNS) alloy
E527 Practice for Numbering Metals and Alloys in the
designations shown in the appendixes are in accordance with
Unified Numbering System (UNS)
Practice E527.
3. Basis of Codification
1.3 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3.1 The designations for alloys and unalloyed metals are
ization established in the Decision on Principles for the
based on their chemical composition limits.
Development of International Standards, Guides and Recom-
NOTE 1—For unalloyed magnesium, magnesium-alloys, cast and
mendations issued by the World Trade Organization Technical wrought, standard limits for alloying elements and impurities are ex-
pressed to the following places:
Barriers to Trade (TBT) Committee.
Less than 0.0001 % (used only for magnesium alloys) 0.0000X
0.0001 to 0.001 % 0.000X
2. Referenced Documents
0.001 to 0.01 % 0.00X
0.01 to 0.10 %
2.1 The following documents form a part of this practice to
Unalloyed aluminum made by a refining process 0.0XX
the extent referenced herein:
Alloys and unalloyed aluminum or magnesium not 0.0X
2 made by a refining process
2.2 ASTM Standards:
0.10 through 0.55 % 0.XX
B80 Specification for Magnesium-Alloy Sand Castings
Over 0.55 % 0.X, X.X, XX.X
B90/B90M Specification for Magnesium-Alloy Sheet and
3.2 Designations shall be assigned, revised, and cancelled
Plate
by Subcommittee B07.04 of ASTM Committee B07 on Light
B91 Specification for Magnesium-Alloy Forgings
Metals and Alloys on written requests to its chairman. Com-
B92/B92M Specification for Unalloyed Magnesium Ingot
plete chemical composition limits shall be submitted with
and Stick For Remelting
request for assignment or revision of designations. Arbitrary
B93/B93M Specification for Magnesium Alloys in Ingot
assignments by other subcommittees or committees will not be
Form for Sand Castings, Permanent Mold Castings, and
recognized.
Die Castings
B94 Specification for Magnesium-Alloy Die Castings
4. Alloys
4.1 Designationforalloysshallconsistofnotmorethantwo
letters representing the alloying elements (Note 2) specified in
This practice is under the jurisdiction of ASTM Committee B07 on Light
the greatest amount, arranged in order of decreasing
Metals and Alloys and is the direct responsibility of Subcommittee B07.04 on
percentages, or in alphabetical order if of equal percentages,
Magnesium Alloy Cast and Wrought Products.
Current edition approved May 1, 2018. Published May 2018. Originally followed by the respective percentages rounded off to whole
approved in 2007. Last previous edition approved in 2011 as B951 – 11. DOI:
numbers and a serial letter (Note 3). The full name of the base
10.1520/B0951-11R18.
metal precedes the designation, but it is omitted for brevity
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
when the base metal being referred to is obvious.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on NOTE 2—For codification, an alloying element is defined as an element
theASTM website. (other than the base metal) having a minimum content greater than zero
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B951−11 (2018)
either directly specified or computed in accordance with the percentages
followed by a 5 only, or a 5 followed only by zeros, the nearest
specified.
even whole number shall be used.
NOTE 3—The serial letter is arbitrarily assigned in alphabetical se-
4.4 When a range is specified for the alloying element, the
quencestartingwith“A”(omitting“I”and“O”)andservestodifferentiate
otherwise identical designations. A serial letter is necessary to complete
rounded mean shall be used in the designation.
each designation.
4.5 When only a minimum percentage is specified for the
4.2 The letters used to represent the two greatest amounts of
alloying element, the rounded minimum percentage shall be
the alloying elements shall be those in Table 1.
used in the designation.
4.3 In rounding percentages, the nearest whole number shall
5. Unalloyed Metals
be used. If two choices are possible as when the decimal is
5.1 Designations for unalloyed metals consist of the speci-
TABLE 1 Letters Representing Alloying Elements
fied minimum purity, all digits retained but dropping the
decimal point, followed by a serial letter (Note 3). The full
A—Aluminum Q—Silver
C—Copper S—Silicon
name of the base metal precedes the designation, but it is
E—Rare earths T—Tin*
omitted for brevity when the base metal being referred to is
H–Thorium* V—Gadolinium
obvious.
J—Strontium W—Yttrium
K—Zirconium Z—Zinc
L—Lithium* *For historical reference
6. Keywords
M—Manganese
6.1 magnesium; UNS designations
B951−11 (2018)
TABLE 2 Unalloyed Magnesium and Magnesium-Alloy Registration
(A Registration Record of Magnesium Alloys with Established Designations and Chemical Composition)
NOTE 1—Cast or wrought product compositions may differ from casting ingot compositions.
Designation Chemical Composition, % max unless shown as a range or as a min
Other Elements
See
Practice UNS
ASTM
Specific Each Total
9980A M19980 B92/ 99.80 0.02 0.10 0.001 0.01 Sn 0.05
B92M min 0.01 Pb
0.006 Na
9980B M19991 B92/ 99.80 0.02 0.10 0.005 0.01 Sn 0.05
B92M min 0.01 Pb
A
9990A M19990 B92/ 99.90 0.003 0.04 0.004 0.001 0.005 0.01
B92M min
A
9995A M19995 B92/ 99.95 0.01 0.003 0.004 0.001 0.005 0.01 Ti 0.005
B92M min
A
9998A M19998 B92/ 99.98 0.004 0.0005 0.002 0.002 0.0005 0.003 0.001 Ti 0.005
B92M min 0.001 Pb
B C D D
AJ52A M17520 B94 4.5-5.5 0.010 0.004 0.24-0.6 0.001 0.10 1.7-2.3 0.22 0.01
BE C
AJ52A M17521 B93/ 4.6-5.5 0.008 0.004 0.26 - 0.001 0.08 1.8-2.3 0.20 0.01
B93M 0.5
B C D D
AJ62A M17620 B94 5.5-6.6 0.010 0.004 0.24-0.6 0.001 0.10 2.0-2.8 0.22 0.01
BE C
AJ62A M17621 B93/ 5.6-6.6 0.008 0.004 0.26-0.05 0.001 0.08 2.1-2.8 0.20 0.01
B93M
C D D
AM50A M10500 B94 4.4-5.4 0.010 0.004 0.26-0.6 0.002 0.10 0.22 0.02
E C
AM50A M10501 B93/ 4.5-5.3 0.008 0.004 0.28-0.50 0.001 0.08 0.20† 0.01
B93M
C
AM60A M10600 B94 5.5-6.5 0.35 0.13-0.6 0.03 0.50 0.22
C
AM60A M10601 B93/ 5.6-6.4 0.25 0.15-0.50 0.01 0.20 0.20 0.30
B93M
C D D
AM60B M10602 B94 5.5-6.5 0.010 0.005 0.24-0.6 0.002 0.10 0.22 0.02
E C
AM60B M10603 B93/ 5.6-6.4 0.008 0.004 0.26-0.50 0.001 0.08† 0.20 0.01
B93M
C
AM100A M10100 B80 9.3-10.7 0.10 0.10-0.35 0.01 0.30 0.30 0.30
B199
B403
C
AM100A M10101 B93/ 9.4-10.6 0.08 0.13-0.35 0.010 0.20 0.2 0.30
B93M
C
AS21A M10210 B94 1.8-2.5 0.01 0.005 0.18-0.7 0.001 0.7-1.2 0.20 0.01
E C
AS21A M10211 B93/ 1.9-2.5 0.008 0.004 0.2-0.6 0.001 0.7-1.2 0.20 0.01
B93M
B C
AS21B M10212 B94 1.8-2.5 0.008 0.0035 0.05-0.15 0.001 0.06-0.25 0.7-1.2 0.25 0.01
BE C
AS21B M10213 B93/ 1.9-2.5 0.008 0.0035 0.05-0.15 0.001 0.06-0.25 0.7-1.2 0.25 0.01
B93M
C
AS41A M10410 B94 3.5-5.0 0.06 0.20-0.50 0.03 0.50-1.5 0.12
C
AS41A M10411 B93/ 3.7-4.8 0.04 0.22-0.48 0.01 0.60-1.4 0.10 0.30
B93M
C D D
AS41B M10412 B94 3.5-0.7 0.02 0.0035 0.35-0.7 0.002 0.50-1.5 0.12 0.02
E C
AS41B M10413 B93/ 3.7-4.8 0.015 0.0035 0.35-0.6 0.001 0.60-1.4 0.10 0.01
B93M
C
AZ31B M11311 B90/ 2.5-3.5 0.04 0.05 0.005 0.20-1.0 0.005 0.10 0.6-1.4 0.30
B90M
B91
B107/
B107M
B843
Magnesium
Aluminum
Calcium
Copper
Gadolinium
Iron
Lithium
Manganese
Neodymium
Nickel
Rare Earths
Silicon
Silver
Strontium
Yttrium
Zinc
Zirconium
B951−11 (2018)
TABLE2 Continued
Designation Chemical Composition, % max unless shown as a range or as a min
Other Elements
See
Practice UNS
ASTM
Specific Each Total
C F
AZ31C M11312 B107/ 2.4-3.6 0.10 0.15-1.0 0.03 0.10 0.50-1.5 0.30
B107M
C
AZ31D M11313 B843 2.5-3.5 0.04 0.04 0.002 0.20-1.0 0.0010 0.05 0.6-1.4 0.01 0.30
C
AZ61A M11610 B91 5.8-7.2 0.05 0.005 0.15-0.5 0.005 0.10 0.40-1.5 0.30
B107/
B107M
C
AZ63A M11630 B80 5.3-6.7 0.25 0.15-0.35 0.01 0.30 2.5-3.5 0.30
C
AZ63A M11631 B93/ 5.5-6.5 0.20 0.15-0.35 0.010 0.20 2.7-3.3 0.30
B93M
C
AZ63B M11632 B843 5.3-6.7 0.02 0.003 0.15-0.7 0.002 0.10 2.5-3.5 0.30
C
AZ63C M11634 B843 5.3-6.7 0.05 0.003 0.15-0.7 0.003 0.30 2.5-3.5 0.30
C
AZ63D M11636 B843 5.0-7.0 0.10 0.003 0.15-0.7 0.003 0.30 2.0-4.0 0.30
C
AZ80A M11800 B91 7.8-9.2 0.05 0.005 0.12-0.5 0.005 0.10 0.20-0.8 0.30
B107/
B107M
C
AZ81A M11810 B80 7.0-8.1 0.10 0.13-0.35 0.01 0.3
...