What 4F means
The number is the position and the letter is the weld type. 4 is overhead, F is a fillet weld — so a 4F test is an overhead fillet weld, welded from underneath a horizontal plate with the weld metal fighting gravity. It is the fillet position welders most often fail on first attempt.
The positions run:
- 1F flat
- 2F horizontal
- 3F vertical
- 4F overhead
For groove welds the equivalent ladder is 1G to 4G, with 6G and 6GR used for pipe.
What a 4F qualification actually covers
A qualification is not limited to the exact position tested. Standards set a range of qualification, and a test in a more difficult position normally extends to the simpler ones. A 4F fillet test, for example, covers 1F, 2F and 4F.
The exact range depends on the standard, the process, the material group and the test authority, so read the certificate rather than assuming — the range is written on it. What a welder is qualified for on paper is what an inspector will accept on site.
How it differs from a trade certificate
A trade certificate, such as a Certificate III in Engineering – Fabrication Trade, records that someone completed an apprenticeship and can fabricate. It says nothing about whether their welds meet AS/NZS 1554.1 for a specific process and position.
Qualification is a test: a test piece welded under observation, then examined — visual inspection plus macro or fracture testing for fillets — with the result recorded against the welder’s name, the process, the position and the standard. Projects specify the qualification; nobody specifies a trade certificate.
What the test involves
- A test piece prepared to the standard, welded in the 4F position with the process being qualified (typically GMAW or MMAW).
- Weld profile checked visually — leg length, throat thickness, undercut, spatter, stop-start quality.
- A macro section or fracture test through the weld to confirm fusion and root penetration.
- Results recorded and issued as a qualification certificate by a recognised test authority.
What to have ready before booking
Current certificates for the process and positions already held, the standard the project specifies, the material group involved, and the joint details from the drawings. If a project asks for AS/NZS 1554.1 SP welding, the qualification needs to match the procedure that will actually be used on the job.
When a welder needs to requalify
Qualifications stay valid while the welder keeps working with the process. A long break from that process, a change of process, or a change to an essential variable in the procedure usually means revalidation. Confirm the interval with the test authority before quoting a project — it is their record that matters, not the welder’s recollection.