ISO 9606-1: welder qualification validity and revalidation

EN ISO 9606-1 (PN-EN ISO 9606-1 in Poland) describes the qualification test for a welder who welds steel manually or semi-automatically, for example with covered electrodes (111), MAG (135, 136, 138), TIG (141) or oxy-fuel gas welding (311). A certificate issued to this standard tells the employer, the auditor and the customer which joints you are allowed to weld and until when. It is relevant to steel welders and to managers who keep track of the validity of their people's qualifications.

Which edition of the standard applies

In Poland the applicable standard is PN-EN ISO 9606-1:2017-10 “Qualification testing of welders. Fusion welding. Part 1: Steels”. It implements EN ISO 9606-1:2017, which is identical to ISO 9606-1:2012 with corrigendum Cor 1:2012. The second corrigendum, Cor 2:2013, concerns only the French language version and does not change the technical content. The 2017 edition added Annexes ZA and ZB, which link the standard to Directives 2014/68/EU (pressure equipment) and 2014/29/EU (simple pressure vessels).

ISO confirmed the 2012 edition in 2023, but the standard is under revision. In 2026 the draft ISO/DIS 9606 appeared, which merges the existing parts 1 to 5 into one document. It is still a draft, so examining bodies test welders and revalidate qualifications in accordance with the 2017-10 edition.

Who it applies to and how it differs from other documents

The standard covers manual and partly mechanised welding, that is welding in which you guide the electrode, torch or blowpipe yourself. Semi-automatic MAG falls within this scope. Fully mechanised and automatic welding is outside it.

EN ISO 14732 (PN-EN ISO 14732 in Poland) applies to welding operators and weld setters of mechanised and automatic equipment, for example a robot or a welding tractor. The current international edition is ISO 14732:2025, in Poland PN-EN ISO 14732:2026-01. It is a separate test with its own validity rules.
The welder's book (książka spawacza) is a Polish document issued by Łukasiewicz-GIT (the former Instytut Spawalnictwa, the Polish Welding Institute) to graduates of courses. The examiner enters test results in it. PRS (Polish Register of Shipping) accepts it as proof of completed training. The range checked by an auditor, however, follows from the test certificate in accordance with ISO 9606-1.
Aluminium is a separate part of the standard, ISO 9606-2. A certificate for steel does not cover it.

Test variables

The certificate covers a specific set of variables, each with an abbreviation in the designation.

Variable	Abbreviations	What it means for you
Process (ISO 4063)	111, 135, 136, 138, 141, 311	A change of process usually means a new test. Exceptions: 135 and 138 cover each other, and 141 also covers 142, 143 and 145. Short-circuit transfer in 131, 135 and 138 covers the other types of metal transfer, but not the other way round.
Product type	P (plate), T (pipe)	A pipe with a diameter of more than 25 mm also covers plates.
Type of weld	BW (butt weld), FW (fillet weld)	A butt weld does not cover a fillet weld without an additional test.
Filler material group	FM1 to FM6	FM1 means filler materials for non-alloy and fine-grain steels, FM5 those for stainless steels. The range is determined by the filler material group, not the steel grade.
Type of filler material	A, R, RA, RB, RC, RR, B, C; S, M, P, V, W, Y, Z; nm	Electrodes: for example B basic, C cellulosic. Wires: S solid, M metal-cored. nm means no filler material.
Dimensions	s, t, D	s is the deposited thickness in a butt weld, t the material thickness, D the outside diameter of the pipe.
Position (ISO 6947)	PA, PB, PC, PD, PE, PF, PG, PH, PJ, H-L045, J-L045	PF and PH are vertical up, PG and PJ vertical down. H-L045 and J-L045 denote a pipe inclined at 45 degrees.
Weld details	ss, nb, mb, bs, gb; sl, ml	ss single side, nb no backing, mb material backing, bs both sides, gb gas backing. sl and ml are single layer or multi-layer in a fillet weld.

How to read a certificate designation: an example

Below is a made-up example, arranged like a typical designation. The order of the elements is set by clause 11 of the standard.

ISO 9606-1 135 P BW FM1 S s10 PF ss nb

ISO 9606-1: the test standard, steels.
135: MAG welding with solid wire.
P: test piece made of plate.
BW: butt weld.
FM1: filler material for non-alloy and fine-grain steels, for example S235 and S355.
S: solid wire.
s10: deposited thickness 10 mm.
PF: vertical position, welding upwards.
ss nb: single-side welding without backing, you form the root yourself.

The shielding gas is entered on the certificate in a separate field, not in the designation.

Range of qualification: what the test result gives you

The range for this example:

Element	In the test	Range of qualification
Process	135	135 and 138
Product type	plate	plates and pipes with an outside diameter of 500 mm or more (smaller pipes too if rotated)
Type of weld	BW	butt welds only
Filler material	FM1, S	FM1 and FM2, solid wire S and wire M
Thickness	s = 10 mm	3 to 20 mm
Position	PF	PA and PF
Details	ss nb	including ss nb, ss mb and bs

General rules:

Butt weld: for s from 3 to 12 mm (excluding 12) the range is 3 mm to 2s. For s of 12 mm or more, if the joint has at least 3 layers, you get a range from 3 mm with no upper limit.
Fillet weld: for t of 3 mm or more the range starts at 3 mm with no upper limit. For thinner plates it is t to 2t, but at least up to 3 mm, for example t = 1.4 mm gives 1.4 to 3 mm.
Pipe diameter: up to 25 mm the range is D to 2D, above 25 mm from 0.5D, but not less than 25 mm.
Butt weld positions: PC covers PA and PC, PE covers PA, PC and PE, PH on a pipe covers PA, PE, PF and PH. H-L045 covers all positions except vertical down (PG, PJ, J-L045). PG covers only PG.
Fillet weld positions: PB covers PA and PB, PF on plate covers PA, PB and PF.
Filler material groups: FM1 and FM2 cover each other, FM3 covers FM1 to FM3, FM4 covers FM1 to FM4, FM5 only FM5, and FM6 covers FM5 and FM6.
A basic electrode (B) also covers rutile and acid electrodes, but not cellulosic (C). It does not work the other way round.
Single layer (sl) covers only sl, multi-layer (ml) covers ml and sl.
To also weld fillet welds with a BW certificate, you need an additional fillet weld test (plate at least 10 mm, single layer, position PB) or a combined test piece in accordance with Annex C.

Testing of the test piece

A plate test piece is at least 200 mm long, and 150 mm of it is assessed. The examiner supervises the welding and marks the test piece. Every test piece undergoes visual testing; further tests depend on the type of weld.

Test	Butt weld (BW)	Fillet weld (FW)
Visual (ISO 17637)	mandatory	mandatory
Radiographic (ISO 17636)	one of three: radiography, bend test or fracture test	not mandatory, on pipes it may replace the fracture test
Bend test (ISO 5173)	as above	not applicable
Fracture test (ISO 9017)	as above	mandatory, or at least 2 macro sections (ISO 17639), including one from the restart location

When you test a butt joint radiographically and weld with process 131, 135, 138 or 311, an additional bend or fracture test is added.
For ferritic steels of 8 mm or more, radiography may be replaced by ultrasonic testing (ISO 17640).
For bend testing of joints thinner than 12 mm, 2 root bend and 2 face bend specimens are taken; for thicker joints, 4 side bend specimens.
Assessment in accordance with ISO 5817: level B, and for a few imperfections, including excess weld metal, excessive convexity and excessive penetration, level C.

Validity and revalidation of qualification

When the validity period starts

Validity begins on the day the test piece is welded, provided the tests are passed. You do not count it from the date the document is issued.

Confirmation every 6 months

Every 6 months the person responsible for welding at your employer (the welding coordinator), or the examiner or examining body, confirms on the certificate that you have welded within the range of qualification. Without confirmation the certificate loses its validity. If you have not welded within the range of qualification for half a year, there is nothing to confirm.

Three revalidation methods under clause 9.3

Revalidation is carried out by the examiner or examining body. The option is marked on the certificate when it is issued, so agree it with the body before the test.

Option	What you have to do	Period
a)	A new test.	3 years
b)	Two welds made in the last 6 months of validity, tested radiographically, ultrasonically or destructively (fracture or bend test), with recorded results. The welds reproduce the test conditions, except for thickness and outside diameter.	2 years
c)	No test, provided that: you work for the same manufacturer who is responsible for the product; its quality system has been verified in accordance with ISO 3834-2 or ISO 3834-3; the manufacturer documents that your welds are of acceptable quality in accordance with the product standards, in the same positions, type of weld (BW or FW) and backing (mb or nb).	no time limit, as long as there are confirmations every 6 months and the conditions are met

For pressure equipment of categories II, III and IV under Directive 2014/68/EU, option c) is not permitted (Annex ZA). In that case the certificate and revalidations a) and b) are handled by a notified body or a recognised third-party organisation.

Typical mistakes

A gap in the 6-monthly confirmations. The certificate ceases to be valid.
Counting validity from the date of issue instead of from the day the test piece was welded.
Welding outside the range: fillet welds with a BW-only certificate, or stainless steel with FM1.
Option b) based on welds made before the last 6 months of validity.
Option c) for pressure equipment of categories II, III and IV, or after a change of employer.

How to prepare and what to bring to the test

Agree with your employer on the range you need in production: process, BW or FW, thicknesses, positions. A pipe in H-L045 gives a wider range of positions than a plate in PF.
Ask for the WPS for the test and practise exactly to it: the same thickness, bevel preparation, filler material and position. The WPS must be at the test station.
Practise stopping and restarting. In the test there must be at least one stop and restart in the root run and one in the capping layer, and the examiner marks them.
Fracture your own fillet welds. The fracture surface will immediately show lack of root penetration and lack of fusion.
Prepare your documents. At PRS, for first certification you need an application, a copy of the training completion certificate or the welder's book and a current medical certificate, and you must also be of legal age. Bring an identity document, and check your examining body's requirements before the test date.
The theoretical part is recommended in the standard, not mandatory (Annex B), but the bodies do run it. At PRS it is a test of 25 questions in 60 minutes, and the pass mark is 15 correct answers.

Train with the same process you are taking the test in. If you do not have a MIG/MAG or TIG machine in your workshop, you can hire a welding machine for the preparation period or buy a used welding machine that stays in the company after the test.

Frequently asked questions

How long is a welder certificate under ISO 9606-1 valid?

With option a) 3 years, with b) 2 years, with c) no time limit. Every option requires the 6-monthly confirmation.

Who signs the confirmation every six months?

The person responsible for welding at the employer, usually the welding coordinator, or the examiner or examining body.

What happens to the certificate when you change jobs?

The certificate is yours, but the confirmations every 6 months must continue without a break. Option c) no longer applies, because it is tied to the manufacturer.

Does a test on plate cover pipes?

Partly: pipes with an outside diameter of 500 mm or more, and smaller pipes too if they are rotated during welding (clause 5.3 of the standard). The other way round is easier: a pipe with a diameter of more than 25 mm covers plates.

Can I weld fillet welds with a butt weld certificate?

Not directly. You need an additional fillet weld test or a combined test piece in accordance with Annex C.

ISO 9606-1 welder certificate: designation, range and revalidation