🔩 Transverse tensile test of welded joints — PN-EN ISO 4136

Materials and NDT PN-EN ISO 4136

Overview

WHAT THIS TEST PROVIDES (clause 1 of ISO 4136:2022 and the PKN card): the specimen dimensions and the procedure of the transverse tensile test for determining the TENSILE STRENGTH and the LOCATION OF FRACTURE of a butt-welded joint. It applies to metallic materials in all product forms, with joints made by any welding process. The standard has no tensile method of its own: except where it provides otherwise, the general principles of ISO 6892-1 (room temperature) and ISO 6892-2 (elevated temperature) apply. That is why in the accreditation scopes the standard almost always stands together with PN-EN ISO 6892-1 — in 20 of 25 entries, most often as "PN-EN ISO 6892-1:2020-05 Metoda B" [Metoda = method] — PN-EN ISO 4136 says HOW TO CUT and PREPARE the specimen from the joint, and PN-EN ISO 6892-1 HOW TO PULL it.

PRINCIPLE (clause 5): a specimen taken transversely from the joint is loaded with an increasing tensile force until fracture. The test is carried out at an ambient temperature of 10 °C to 35 °C, unless otherwise agreed; tests under controlled conditions — at (23 ± 5) °C. The temperature is given in the report. This part of the principle changed in the 2022 edition: according to the foreword, the requirement for the ambient temperature was aligned with ISO 6892-1.

TAKING AND PREPARING THE SPECIMEN (clause 6): • the specimen is cut transversely so that after machining the weld axis lies in the middle of the parallel length (6.1); pipes of small diameter — by default D ≤ 50 mm — can be tested in full section; • each specimen and test piece is marked so that their exact position in the product is known; if required by the product standard — also the direction of working (6.2); • no heat treatment of the joint or the specimen, unless permitted by the product standard; with natural ageing of aluminium alloys the time from welding to testing is recorded; hydrogen in the weld metal of steels may change the result and require a hydrogen-removal treatment (6.3); • STEEL: shearing excluded for thicknesses above 8 mm; thermal cutting at least 8 mm from the surface of the finished parallel length and never parallel to the plate surface. OTHER METALS: shearing and thermal cutting excluded — only machining, e.g. sawing, water-jet cutting, milling (6.4); • the thickness of the specimen usually equals the thickness of the parent metal at the joint; where testing of the full thickness above 30 mm is required, several specimens may be taken through the thickness, stating the position of each (6.5.2). DIMENSIONS OF SPECIMENS FROM PLATES AND PIPES (Table 2): width of the parallel length bO — plates: 12 mm for ts ≤ 2 mm, 25 mm for ts > 2 mm; pipes: 6 mm for D ≤ 50 mm, 12 mm for 50 < D ≤ 168.3 mm, 25 mm for D > 168.3 mm; parallel length Lc ≥ Ls + 60 mm (Ls — the maximum width of the weld after machining; for resistance welding, pressure welding and beam welding Ls = 0); for aluminium, copper and their alloys Lc ≥ Ls + 100 mm may be necessary; transition radius r ≥ 25 mm; width of the grip end bO + 12 mm.

WHERE AN ERROR HIDES BEHIND A SEEMINGLY CORRECT RESULT: a steel specimen thermally cut too close to the parallel length (less than 8 mm) or — with other metals — thermally cut at all. The heat-affected zone of the cut changes the properties of the material at the edge, and the test gives a number that looks correct.

EDITIONS (state of the PKN cards and the ISO website on 25.09.2026). PN-EN ISO 4136:2022-12 — English-language version, publication 06-12-2022, 22 pages, KT 165 Welding and Allied Processes; it implements EN ISO 4136:2022 and ISO 4136:2022 [IDT]; it replaces PN-EN ISO 4136:2013-05 (English-language and German-language versions), withdrawn on 06-12-2022. The card has no "Withdrawn" header. ISO website: ISO 4136:2022 — edition 4, published 2022-05, stage 60.60. Changes of the 2022 edition according to the foreword: ambient temperature as in ISO 6892-1, updated Table 1 and figures, clarified pipe diameters and determination of the cross-section SO, bibliography added.

HOW ACCREDITATION SCOPES CITE THE STANDARD. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 25 entries at 18 laboratories — "PN-EN ISO 4136:2022-12" (21), "PN-EN ISO 4136" without a year (3), "PN EN ISO 4136:2022-12" (1). Object: welded joints, including "nienapromienione i napromienione" [non-irradiated and irradiated]. Methodology: "Właściwości mechaniczne" / "Własności mechaniczne" [mechanical properties] with the parameters: tensile strength Rm, maximum force Fm, yield strength Re and proof strength Rp, elongation A, reduction of area Z; machine forces "do 600 kN", "do 1000 kN" [do = up to]. The standard speaks of the tensile strength and the location of fracture — the other quantities (Re, Rp, A, Z) come from PN-EN ISO 6892-1, and on a transverse specimen they cover the weld, the heat-affected zone and the parent metal at the same time.

THE KEY OF THE "LABORATORIES" TAB: "PN-EN ISO 4136" — 17 laboratories and 24 entries, without any foreign entries; it will not show one laboratory (AB 099) with the notation "PN EN ISO 4136:2022-12" without a hyphen.

HOW FAR THE TEXT EXTENDS: the extract of ISO 4136:2022 made available by the publisher covers clauses 1–6 up to 6.5.3.3 (specimens from solid sections). We do not have the test procedure, the requirements for the report or the figures with the dimensions of full-pipe specimens.

Method principle

A specimen is cut from a butt-welded joint transversely to the weld so that the weld axis falls in the middle of its parallel length, machined to the dimensions of Table 2 and pulled with an increasing force until fracture according to the principles of ISO 6892-1 (or ISO 6892-2 at elevated temperature). The result is the tensile strength of the joint and the location of fracture — in the weld, in the heat-affected zone or in the parent metal.

Applications

• Qualification of welding procedures and checking of butt joints in metals
• Joints of plates, pipes (also whole pipes of small diameter) and solid sections
• Joints of steel, aluminium, copper and their alloys — with different requirements for cutting specimens
• Irradiated joints — in the accreditation scopes

Key parameters

Standard

Standard number

PN-EN ISO 4136:2022-12 (wersja angielska; wprowadza EN ISO 4136:2022 [IDT], ISO 4136:2022 [IDT])

Title (PL)

Badania niszczące złączy spawanych metali — Próba rozciągania próbek poprzecznych

Title (EN)

Destructive tests on welds in metallic materials — Transverse tensile test

Step-by-step procedure

1. Sampling plan

   The position of the specimens in the joint and any heat treatment are specified by the product standard; specimens and test pieces are marked with their position.

2. Cutting

   Steel: shearing only up to 8 mm thickness, thermal cutting ≥ 8 mm from the parallel length; other metals: machining only.

3. Machining to dimensions

   Weld axis in the middle of the parallel length; dimensions from Table 2 (bO, Lc ≥ Ls + 60 mm, r ≥ 25 mm); tolerances according to ISO 6892-1 and 6892-2; for pipes, flattening of the grip ends must not extend into the parallel length.

4. Measuring the cross-section

   Determine the original cross-section SO of the parallel length.

5. Tensile loading

   With an increasing force until fracture, according to the principles of ISO 6892-1 (or 6892-2); temperature 10–35 °C or (23 ± 5) °C under controlled conditions.

6. Result and report

   Tensile strength, location of fracture and test temperature; with natural ageing of Al alloys — the time from welding to testing.

Required equipment and apparatus

Health and safety (OHS)

• Fracture of the specimen under a high force — machine guards, safety zone
• Cutting and machining of specimens — eye and hearing protection, guards on saws and milling machines
• Irradiated joints — the laboratory's radiological protection procedures

Frequently asked questions