ASTM B91-12 - 1.11.2012
 
1. Scope

1.1 This specification covers magnesium alloy forgings designated as shown in Table 1.

TABLE 1 Chemical Composition LimitsA,B
Note 1—Analysis shall regularly be made only for the elements specifically mentioned in this table. If, however, the presence of other elements is suspected or indicated in amounts greater than the specified limits, further analysis shall be made to determine that these elements are not present in excess of the specified limits.
Note 2—The following applies to all specified limits in this table. For purposes of acceptance and rejection, an observed value or a calculated value obtained from analysis should be rounded to the nearest unit in the last right-hand place of figures used in expressing the specified limit.

 

Composition, %

Element

Alloy AZ31B
  (UNS No.
  M11311)

Alloy AZ61A
  (UNS No.
  M11610)

Alloy AZ80A
  (UNS No.
  M11800)

Alloy ZK60A
  (UNS No.
  M16600)

   Magnesium

  remainder

  remainder

  remainder

  remainder

   Aluminum

  2.5–3.5

  5.8–7.2

  7.8–9.2

  ...

   Manganese

  0.20–1.0

  0.15–0.5

  0.12–0.5

  ...

   Zinc

  0.6–1.4

  0.40–1.5

  0.20–0.8

  4.8–6.2

   Thorium

  ...

  ...

  ...

  ...

   Zirconium, min

  ...

  ...

 

  0.45

   Silicon

  0.10

  0.10

  0.10

  ...

   Copper

  0.05

  0.05

  0.05

  ...

   Nickel

  0.005

  0.005

  0.005

  ...

   Iron

  0.005

  0.005

  0.005

  ...

   Calcium

  0.04

  ...

  ...

  ...

   Other impuritiesC

  0.30

  0.30

  0.30

  0.30

A Limits are in weight percent maximum unless shown as a range or stated otherwise.
B  These alloy designations were established in accordance with Practice B951.
C  Includes listed elements for which no specific limit is shown.

1.2 The values stated in inch-pound units are the standard. The SI values in parentheses are provided for information only.

 
2. Referenced Documents

B954-23

Standard Test Method for Analysis of Magnesium and Magnesium Alloys by Atomic Emission Spectrometry

E29-22

Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications

E55-23

Standard Practice for Sampling Wrought Nonferrous Metals and Alloys for Determination of Chemical Composition

No. 184

Identification Marking of Aluminum, Magnesium, and Titanium.

MIL-STD-129

Marking for Shipment and Storage

B951-11(2025)

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

B953-21

Standard Practice for Sampling Magnesium and Magnesium Alloys for Spectrochemical Analysis

B557-15(2023)

Standard Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products

B660-23

Standard Practices for Packaging/Packing of Aluminum and Magnesium Products