ASTM B557 Tension Testing for Wrought and Cast Aluminum and Magnesium Alloy Products

ASTM B557: Standard Test Methods for Tension Testing Wrought and Cast Aluminum- and Magnesium-Alloy Products

ASTM B557 is a tensile testing standard focused specifically on wrought and cast aluminum- and magnesium-alloy products. The current ASTM catalog listing identifies the active edition as ASTM B557-15(2023).

This document is a set of test methods rather than a product specification. It defines how tensile testing is performed and how strength and ductility data are generated for these alloy products.

Quick Definition

In practical terms, ASTM B557 provides the framework for pulling a standardized aluminum- or magnesium-alloy test specimen in uniaxial tension and recording the resulting mechanical response for comparison, quality control, and acceptance work.

What This Standard Covers

ASTM B557 covers tension testing of wrought and cast aluminum- and magnesium-alloy products, except aluminum foil. ASTM notes that these test methods are derived from ASTM E8, the broader metallic materials tension testing standard.

For ASTM B557, inch-pound units are the standard units. ASTM also maintains a metric companion document, ASTM B557M, for users working to metric tensile specimen and reporting conventions.

The standard is used to test specimens prepared to standardized dimensions from selected portions of a product or part. Because of that, the results are highly useful for material comparison and acceptance work, but they may not fully represent the behavior of the finished part in service.

Why This Standard Matters in Testing

ASTM B557 matters because it creates a consistent basis for tensile property data on aluminum and magnesium alloys. The standard is used to generate strength and ductility information under uniaxial tensile loading, which supports alloy development, quality control, and design decisions.

It is also recognized as suitable for acceptance testing of commercial shipments. When a purchase order, material specification, or drawing calls out ASTM B557, the exact cited edition can affect specimen details, units, and reporting expectations.

Common Materials, Product Types, or Applications Covered

The standard applies to wrought aluminum-alloy products, cast aluminum-alloy products, wrought magnesium-alloy products, and cast magnesium-alloy products. In day-to-day lab use, that usually means representative tensile specimens taken from mill products, castings, or qualification coupons made from those alloys.

ASTM B557 is most relevant wherever lightweight nonferrous metals must be checked for tensile performance before release, comparison, or acceptance. It is not the standard for aluminum foil testing, so thin foil programs should be matched to the correct separate method.

Common Test or Verification Workflow

A typical ASTM B557 workflow starts with selecting a representative test location and preparing a specimen to the geometry required by the cited edition and material form. The specimen is then mounted in a tensile frame so the applied load is as axial as possible through the gage section.

During the test, force is increased in tension while force and elongation are recorded as needed for the required properties. The resulting data are used to report mechanical response such as strength and ductility values for comparison, conformance, or lot release.

Because specimen shape, gage details, and reporting can vary with the cited edition and the associated product specification, machine setup should be matched to the exact document callout before testing begins.

Equipment Commonly Used for This Standard

ASTM B557 commonly points to a universal testing machine with appropriate force capacity for aluminum or magnesium tensile work. The equipment path usually includes tensile grips suited to the specimen style, such as flat or round specimens, and enough alignment control to avoid introducing unnecessary bending.

Where the test program requires strain-based values or controlled elongation measurement, labs typically add an extensometer or other suitable strain measurement system matched to the specimen gage length and expected strain range. Specimen machining and dimensional measurement tools are also part of the workflow because specimen geometry directly affects the validity of the results.

For equipment selection, the most important practical caution is matching grip style, force range, and strain measurement to the actual specimen form being tested rather than choosing a generic tensile frame alone.

How to Read This Designation or Revision

In ASTM B557, the letter B identifies ASTM’s nonferrous metals and products classification, and 557 is the sequential document number. In the active listing ASTM B557-15(2023), the 15 identifies the revision year and the year in parentheses identifies the later reapproval year.

If you see ASTM B557M, the M indicates the metric companion standard. That distinction matters when you are reviewing specimen dimensions, gage lengths, units, and reporting format for a quote or lab procedure.

Related Standards, Methods, or Frameworks

ASTM B557 is derived from ASTM E8, which is the broader ASTM tensile testing framework for metallic materials. Many labs and manufacturers use ASTM E8/E8M as the general reference point, then apply ASTM B557 when the material scope specifically involves wrought or cast aluminum and magnesium alloys.

ASTM B557M is the closest companion reference when the same testing approach is needed in metric form. Product specifications and procurement documents may also call out ASTM B557 as the required tensile test method for acceptance or qualification of a particular alloy product.

Get Help With ASTM B557 Equipment Selection

If you are planning an ASTM B557 test setup, we can help match machine capacity, grip style, extensometer approach, and specimen handling to your aluminum or magnesium application. For pricing on a suitable configuration, Request a Quote.