🔩 Tension test of metals at room temperature (10–38 °C) according to ASTM — yield strength, yield point elongation, tensile strength, elongation and reduction of area; gauge length 4D (E8) or 5D (E8M); ASTM E8/E8M

Materials and NDT ASTM E8

Overview

WHAT THE STANDARD COVERS. Scope of ASTM E8/E8M-25 according to the publisher's page (store.astm.org, read on 10.10.2026): the test methods cover the tension testing of metallic materials in any form at room temperature, specifically the methods of determination of yield strength, yield point elongation, tensile strength, elongation and reduction of area (1.1). The gauge lengths for most round specimens are 4D for E8 and 5D for E8M — this is the most significant difference between E8 and E8M test specimens; specimens made from powder metallurgy (sintered) materials are exempt from this requirement by industry-wide agreement (1.2). Exceptions to the provisions may be made by specifications or test methods for specific materials — e.g. ASTM A370 and B557/B557M (1.3). Room temperature is 10–38 °C [50–100 °F] unless otherwise specified (1.4). The values stated in SI units and in inch-pound units are separate from each other and are not exact equivalents; each system is used independently, and combining values from the two systems may result in non-conformance with the standard (1.5). ASTM Committee E28.

SIGNIFICANCE AND USE (section 4 according to the same page). The tension test provides information on the strength and ductility of materials under uniaxial tensile stresses — useful for comparisons of materials, alloy development, quality control and, under certain circumstances, design. Results from specimens machined to standardized dimensions from selected portions of a part or material may not totally represent the strength and ductility of the entire end product or its in-service behaviour in different environments. The methods are considered satisfactory for acceptance testing of commercial shipments and have been used extensively in the trade for this purpose.

EDITIONS. The ASTM store (10.10.2026) lists E8/E8M-25 as the active edition, and earlier ones including E8/E8M-24, -22 and -21. In the iTeh catalogue the E8/E8M-24 edition has a publication date of 01.01.2024 (35 pages). ASTM has no Polish edition of this standard — the accreditation scopes carry the ASTM designation, and the Polish title above is our translation.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database of 10.10.2026 and current PCA documents read on 10.10.2026). In Polish scopes "ASTM E8" appears in 11 records at 10 laboratories: AB 001 (2 records), AB 019, AB 099, AB 205, AB 372, AB 490, AB 792, AB 812, AB 1283 and AB 1700; the standard is present in all 10 current PCA documents, no entry is suspended. Editions: E8/E8M-25 (AB 490, AB 792, AB 812, AB 1283, AB 1700), E8/E8M-24 (AB 001, AB 205), E8/E8M-21 (AB 099, AB 372), without a year (AB 019). The "Laboratories" tab ("ASTM E8") shows 27 laboratories (measurement on the production server on 10.10.2026): 9 Polish and 18 Czech, including two Czech ones that enter it only through other ASTM standards with numbers beginning with E8 — E837 and E811; it does not include AB 812, which writes "ASTME8/E8M-25" without a space. The form "ASTM E8/E8M" as the key would give only 17 laboratories — without the Czech laboratories writing just "ASTM E8" and without AB 372 and AB 792.

WHAT THE LABORATORIES TEST (copy and PCA documents). Mechanical properties in the static tensile test at room temperature: metals and metal alloys (AB 372, AB 490, AB 792, AB 1283 — cast and wrought form), metals and welded joints (AB 001), rolled steel products (AB 019, AB 812) and open-die forgings (AB 019), steel products (AB 1700), steel and cast products (AB 099), structural products, steel and iron castings (AB 205). AB 792 also has in the same entry the test at elevated temperature (up to 2000 °F; ASTM E21, PN-EN ISO 6892-2) and the modulus of elasticity (ASTM E111) — E8 does not cover these parts. Nine of the ten laboratories have PN-EN ISO 6892-1 in the same entry, five — ASTM A370 (AB 001, AB 019, AB 205, AB 812, AB 1700); AB 001 also PN-EN ISO 4136, PN-EN ISO 5178 and PN-EN ISO 9018.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — E8 or E8M: for round specimens the gauge length of 4D (E8) or 5D (E8M) changes the elongation; an elongation result without stating the version cannot be compared with a requirement. Second — mixing units: inch-pound and SI values are not exact equivalents, and combining them may result in non-conformance with the standard (1.5). Third — the product specification takes precedence: for steel the exceptions of ASTM A370 apply, for aluminium — those of B557/B557M (1.3). Fourth — representativeness: a result from a specimen cut from a selected location need not describe the entire product (4.2). Fifth — ASTM E8 is not ISO 6892-1: these are two different standards with a similar purpose; reporting a result from one as a result according to the other requires the test to be carried out according to it.

WHAT WE DO NOT GIVE. We have not read the content of the standard beyond the scope (section 1) and significance (section 4) from the publisher's page — we do not give specimen dimensions, testing speeds, methods of determining the yield strength (e.g. offset), rounding or requirements for the machine and extensometer.

Method principle

A metal specimen of standardized dimensions is pulled uniaxially at room temperature (10–38 °C) and the yield strength, yield point elongation, tensile strength, elongation and reduction of area are determined; for most round specimens the gauge length is 4D (E8, inch-pound units) or 5D (E8M, SI), and the two systems of units are not mixed (ASTM E8/E8M-25, 1.1–1.5, according to the publisher's page). We DO NOT GIVE the details of the procedure.

Applications

• Metals in any form — comparison of materials, alloy development, quality control, under certain circumstances design (4.1)
• Acceptance testing of commercial shipments — a method used extensively in the trade (4.3)
• In the accreditation scopes: 10 Polish laboratories (editions -21, -24, -25 and without a year)

Key parameters

Standard

Standard number

ASTM E8/E8M-25

Title (PL)

Metody badań rozciągania materiałów metalowych (tłumaczenie tytułu nasze; norma ASTM nie ma polskiego wydania)

Title (EN)

Standard Test Methods for Tension Testing of Metallic Materials

Step-by-step procedure

1. Choice of version and specification

   Establish E8 (inch-pound, 4D) or E8M (SI, 5D) and the product specification with any exceptions (e.g. ASTM A370, B557/B557M).

2. Specimen

   Specimen of standardized dimensions from a selected location of the product; we DO NOT GIVE the dimensions.

3. Tension test

   Uniaxial tension at 10–38 °C; we DO NOT GIVE speeds or methods of determining the yield strength.

   🌡 Temperature: 10–38 °C

4. Result

   Yield strength, yield point elongation, tensile strength, elongation, reduction of area — in one system of units; state the version (E8/E8M) and the edition (active E8/E8M-25, state on 10.10.2026).

Required equipment and apparatus

Health and safety (OHS)

• Fracture of the specimen releases elastic energy — machine guards and eye protection
• The standard itself does not address safety concerns; it is the responsibility of the user to establish safety and health practices (1.6)

Frequently asked questions