ASTM A370 : 24a

Name: ASTM A370 : 24a
Brand: ASTM International
SKU: ASTM119276
Price: 101.70 USD
Availability: InStock

Standard Test Methods and Definitions for Mechanical Testing of Steel Products

Standard Details

1.1 These test methods2 cover procedures and definitions for the mechanical testing of steels, stainless steels, and related alloys. The various mechanical tests herein described are used to determine properties required in the product specifications. Variations in testing methods are to be avoided, and standard methods of testing are to be followed to obtain reproducible and comparable results. In those cases in which the testing requirements for certain products are unique or at variance with these general procedures, the product specification testing requirements shall control.

1.2 The following mechanical tests are described:

	Sections
Tension	7 to 14
Bend	15
Hardness	16
Brinell	17
Rockwell	18
Portable	19
Impact	20 to 30
Keywords	32

1.3 Annexes covering details peculiar to certain products are appended to these test methods as follows:

	Annex
Bar Products	Annex A1
Tubular Products	Annex A2
Fasteners	Annex A3
Round Wire Products	Annex A4
Significance of Notched-Bar Impact Testing	Annex A5
Converting Percentage Elongation of Round Specimens to Equivalents for Flat Specimens	Annex A6
Testing Multi-Wire Strand	Annex A7
Rounding of Test Data	Annex A8
Methods for Testing Steel Reinforcing Bars	Annex A9
Procedure for Use and Control of Heat-cycle Simulation	Annex A10

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5 When these test methods are referenced in a metric product specification, the yield and tensile values may be determined in inch-pound (ksi) units then converted into SI (MPa) units. The elongation determined in inch-pound gauge lengths of 2 in. or 8 in. may be reported in SI unit gauge lengths of 50 mm or 200 mm, respectively, as applicable. Conversely, when these test methods are referenced in an inch-pound product specification, the yield and tensile values may be determined in SI units then converted into inch-pound units. The elongation determined in SI unit gauge lengths of 50 mm or 200 mm may be reported in inch-pound gauge lengths of 2 in. or 8 in., respectively, as applicable.

1.5.1 The specimen used to determine the original units must conform to the applicable tolerances of the original unit system given in the dimension table not that of the converted tolerance dimensions.

Note 1: This is due to the specimen SI dimensions and tolerances being hard conversions when this is not a dual standard. The user is directed to Test Methods A1058 if the tests are required in SI units.

1.6 Attention is directed to ISO/IEC 17025 when there may be a need for information on criteria for evaluation of testing laboratories.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.8 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.

What ASTM A370 means for steel mechanical testing

ASTM A370 is the umbrella standard used to run consistent, comparable mechanical tests on steels, stainless steels, and related alloys. It standardizes how labs perform key tests so manufacturers and customers can trust results across mills, batches, and suppliers.

It reduces test-to-test variation by defining consistent procedures and terminology.
It supports product specifications by defining test methods used for acceptance and compliance.
It covers multiple tests in one place: tension, bend, hardness, and impact.

Video credit: ASTM International on YouTube.

Core building blocks of ASTM A370

Tension testing: yield strength, tensile strength, elongation, reduction of area.
Bend testing: ductility and soundness checks through bending requirements.
Hardness testing: Brinell, Rockwell, and portable hardness for production checks.
Impact testing: Charpy notched-bar testing to assess toughness.
Annex guidance: product-specific details for bars, tubes, fasteners, wire, rebar, and more.

Tension testing under ASTM A370

Specimen selection and preparation aligned with the product form.
Correct gauge length and measurement practices.
Reporting yield and tensile values in the correct unit system and converting only as allowed.

Video credit: Namsong TV on YouTube.

Bend testing under ASTM A370

Fixture selection (mandrel/roller) based on product requirements.
Controlled bend angle and inspection for cracking or defects.

Video credit: The Universal Grip Company on YouTube.

Hardness testing (Brinell and Rockwell)

Brinell: useful where a larger indentation provides an averaged hardness result.
Rockwell: fast production hardness checks using common scales such as HRB and HRC.
Portable hardness: convenient verification when lab testing is impractical.

Video credit: Dr.-Ing. Rainer Schwab (Hochschule Karlsruhe) on YouTube.

Video credit: Tinius Olsen on YouTube.

Impact testing (Charpy) under ASTM A370

Measures absorbed energy and fracture behavior to assess toughness.
Supports low-temperature service and fracture resistance verification.
Requires correct notch geometry and specimen conditioning.

Video credit: The Universal Grip Company on YouTube.

High-value use cases of ASTM A370

Steel mills and rolling lines: lot acceptance and certification testing.
Fabrication shops: verifying incoming steel meets spec before welding or machining.
Fasteners and critical hardware: ensuring strength and toughness targets are met.
Construction and infrastructure: compliance support for structural steel and reinforcing bar programs.
Energy supply chains: consistent verification of mechanical properties for demanding services.

Integration with lab quality systems

Supports consistent testing aligned with ISO/IEC 17025 expectations for competent labs.
Works with product standards that reference A370 methods for acceptance requirements.
Improves traceability through clear documentation and repeatable reporting.

Deployment timeline and lab readiness

Week 1: confirm which A370 tests apply to your products and where product specs override general procedures.
Weeks 2–3: validate equipment (UTM, impact tester, hardness testers) and operator training.
Weeks 4–6: finalize SOPs, reporting templates, rounding rules, and conversion rules.

Common pitfalls and how to avoid them

Mixing unit systems: keep inch-pound and SI separate unless conversion is explicitly allowed.
Wrong specimen geometry: specimen must match the original unit system tolerances.
Ignoring product spec overrides: product specification requirements control when they differ.
Poor notch/specimen prep: impact results become unreliable if geometry is off.
Hardness inconsistencies: ensure proper surface prep, correct scale selection, and stable test conditions.

Case study: fewer disputes and faster approvals

A supplier standardized all mechanical testing reports using ASTM A370 methods across tension, bend, hardness, and impact.

Customer disputes dropped because methods were consistent and clearly documented.
Retesting reduced due to improved repeatability and clearer reporting.
Approvals accelerated because reports matched product specification expectations.

Next steps and additional resources

Access ASTM A370 through BSB Edge.
Build a test matrix mapping each product spec requirement to the relevant A370 section.
Train operators on unit handling, reporting, rounding, and conversions.
Maintain calibration and traceability records aligned with lab quality requirements.

Frequently Asked Questions

1. What does ASTM A370 cover?
It covers procedures and definitions for mechanical testing of steels and related alloys across tension, bend, hardness, and impact tests.

2. Does A370 define acceptance values?
A370 defines methods; product specifications define required properties and acceptance criteria.

3. Why does A370 emphasize avoiding variations?
To ensure tests are reproducible and comparable across labs and suppliers.

4. Can I freely convert between SI and inch-pound?
Conversions are governed by the standard and by product specification requirements.