Welder qualification range to EN ISO 9606-1
A qualification does not license you to weld everything. It defines a range — thickness, diameter, position — and this works out where the edges of that range are.
Short answer
A 10 mm plate test covers 3–20 mm; a 114.3 mm pipe test covers 57.2 mm and up. The certificate lasts three years and needs a confirmation every six months. The calculator below gives the range for your test piece.
The rules behind it
Thickness. A test piece of thickness t generally covers from 0.5·t to 2·t, with a lower cap for thin material. Single-run and multi-run test pieces do not cover the same range, which is why table 6 of EN ISO 9606-1 exists.
Diameter. A pipe test of outside diameter D covers from 0.5·D upwards. Anything at or above 500 mm counts as plate, and a plate test covers pipe of 500 mm and larger.
Position. Harder positions cover easier ones. PF covers PA and PB; PA covers little beyond itself. H-L045 on pipe is the broadest single test most welders will take.
| Test piece thickness t, mm | Qualified range |
|---|---|
| t < 3 | from 0.5·t to 2·t |
| 3 ≤ t < 12 | from 3 mm to 2·t |
| t ≥ 12 | from 5 mm upwards |
Validity
Three years, provided the employer signs every six months that you have been working within the range. What the calculator does not model is the parent material group to ISO/TR 15608 and the consumable group — both also limit the range, and both are printed on the certificate. Read the whole code, not just the position: what it means is set out in the qualification test article.
Positions each test covers
| Passed in position | Covers |
|---|---|
| PA — flat | PA |
| PB — horizontal-vertical fillet | PA, PB |
| PC — horizontal | PA, PB, PC |
| PD — overhead fillet | PA, PB, PD |
| PE — overhead | PA, PB, PD, PE |
| PF — vertical up | PA, PB, PF |
| PG — vertical down | PG |
| H-L045 — pipe at 45°, upwards | PA, PB, PC, PD, PE, PF, H-L045 |
Frequently asked questions
My certificate says PF. Can I weld in PA?
Yes. A test in PF covers the easier positions; the rule runs one way only. A test taken in PA covers almost nothing else, which is why examiners suggest PF even though it is harder.
What happens if the six-month confirmation is missed?
The certificate lapses, even though the three years have not run out. This is the most common reason a welder turns up on site with a document that is formally invalid — the signature is the employer's job, but the consequence lands on the welder.
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