Worker guide · 7 min read · updated Nov 2026
Welding positions and certifications explained: 1G to 6G, TIG, ARC and MIG
Welder job ads are full of short codes: "6G TIG/ARC welder", "3G/4G structural welder", "ASME IX qualified". If you are a welder, you probably know them by heart – but employers, recruiters and helpers moving up into welding often do not. This guide explains what each code means and why it changes the salary.
Welding positions
The number tells you the position; the letter tells you the joint type – G for a groove (butt) weld and F for a fillet weld.
| Code | Plate / pipe position |
|---|---|
| 1G / 1F | Flat – the easiest position. On pipe, the pipe is rolled while the welder stays still. |
| 2G / 2F | Horizontal – plate vertical, weld line horizontal; on pipe, the pipe stands vertical. |
| 3G / 3F | Vertical – the weld runs up (or down) a vertical plate. |
| 4G / 4F | Overhead – welding from underneath. Hard on the body and on weld quality. |
| 5G | Pipe fixed horizontal – the welder moves around the pipe, covering flat, vertical and overhead. |
| 6G | Pipe fixed at 45° – the hardest standard test, covering all positions. A 6G qualification generally covers the other positions too. |
That is why "6G pipe welders" are the best paid welding vacancies on refinery, petrochemical and pipeline projects.
Welding processes
- TIG (GTAW – gas tungsten arc welding): slow, precise, very clean. Used for root passes on pipe, stainless steel and thin material.
- ARC / stick (SMAW – shielded metal arc welding): rugged and portable; common for fill and cap passes on pipe and for structural steel.
- MIG / MAG (GMAW): wire-fed and fast; widely used in fabrication workshops and on sheet metal.
- Flux-cored (FCAW): wire-fed with flux inside – productive on structural steel and in shipyards.
- SAW (submerged arc): automatic process used for long welds on heavy plate, tanks and pressure vessels.
"TIG/ARC" in an ad usually means TIG root and hot pass, then ARC fill and cap – the classic combination for carbon-steel pipe.
Codes and qualifications
- ASME Section IX – the qualification code for welders working on pressure vessels and process piping (refineries, petrochemicals, power plants).
- AWS D1.1 – structural steel welding code, common on buildings, bridges and steel structures.
- API 1104 – pipeline welding.
- ISO 9606 / EN 287 – European welder qualification, often requested for jobs in Germany, Norway and other European countries.
A welder qualification certificate (often called a WQT or WPQ) records the process, position, material and thickness range you passed. Keep copies: many employers will retest you anyway, but a recent certificate gets you to the test.
How it affects pay
Looking at the welder vacancies collected on this site, 6G pipe welders on Gulf oil and gas projects are typically offered noticeably more than structural (3G/4G) welders, and Canadian and Norwegian welding jobs pay by the hour at rates several times higher – but require local certification and work permits. Browse current welder jobs to compare.
Moving up from helper to welder
Many welders start as fitter or welder helpers. Practise on scrap coupons in your workshop, ask the welding foreman to watch your passes, and take a formal qualification test as soon as your employer allows. A 3G/4G plate certificate is a good first step; 6G pipe comes next.