Understanding AWS Certification: 6G Tests, WPS & PQR Explained
Welding certification has a vocabulary problem. Job listings ask for 6G. Fabrication drawings reference a WPS. Someone mentions a PQR and everyone nods. For anyone outside the credentialled trade, these read like insider shorthand for a system nobody explains — and the explanations that do exist are usually written for people already inside it. This is the plain-language version: what the terms mean, how the documents relate, and what the process actually involves.
What certification actually certifies
The common misconception is that certification is a general licence — that a certified welder is certified to weld. It is far narrower and far more useful than that. A welder qualification says: this person, using this process, on this material type and thickness range, in this position, following a procedure of this description, produced a test coupon that passed the required examination.
Every one of those qualifiers is load-bearing. Change the process, move outside the qualified thickness range, or weld in a position the test did not cover, and the qualification may not extend to the new work. This is why welders often hold several qualifications and why employers re-test people who arrive with credentials from elsewhere — the paperwork has to match the job in front of them.
The position codes
The alphanumeric codes describe the orientation of the joint during the test. The letter identifies the weld type and the number identifies the position.
| Code | Joint | Position | In practice |
|---|---|---|---|
| 1F / 1G | Fillet / groove | Flat | Work below you, gravity assists — the easiest orientation |
| 2F / 2G | Fillet / groove | Horizontal | Weld axis horizontal; the puddle wants to sag downward |
| 3F / 3G | Fillet / groove | Vertical | Welding up or down a vertical joint; heat control becomes central |
| 4F / 4G | Fillet / groove | Overhead | Working above your head against gravity |
| 5G | Groove, pipe | Fixed horizontal pipe | Pipe cannot rotate; welder travels around it through multiple positions |
| 6G | Groove, pipe | Fixed inclined pipe | Pipe fixed at an angle — combines the difficulties of the others |
The general principle within most codes is that qualifying in a more demanding position extends coverage to less demanding ones, subject to the specific rules of the code in question. That is why a pipe test in a difficult position is worth so much more to an employer than several plate tests in easy ones.
Why 6G carries the reputation
In a 6G test the pipe is fixed at an inclined angle and cannot be turned. To complete the joint the welder has to work continuously around it, passing through flat, vertical and overhead orientations, adjusting technique as the geometry changes under the torch — while maintaining consistent root penetration, bead profile and fusion throughout, and while the joint itself is a pipe rather than a comfortable flat plate.
It is not that any individual portion is uniquely difficult. It is that the test demands all of them in sequence without a break in the weld, which is a real test of positional control rather than of a single practised motion. That combination is why the code appears in job listings as shorthand for a capable pipe welder.
WPS, PQR and welder qualification
These three documents confuse people because their names sound similar and their relationship is not obvious. The relationship is actually straightforward once you see the order they come in.
| Document | What it is | What it answers |
|---|---|---|
| PQR — Procedure Qualification Record | The record of a test weld made to a candidate procedure, with the test results | Does a weld made this way actually meet the requirement? |
| WPS — Welding Procedure Specification | The written instruction derived from and supported by the PQR | How exactly should this weld be made? |
| WPQR — Welder qualification record | The record that a specific welder welded to the procedure and passed | Can this person execute it? |
On a job site, the WPS is the document a welder works to. It specifies process, base material, filler, shielding gas, current and polarity, travel direction, joint preparation, preheat and interpass temperature requirements, and technique. It exists so that the weld being made now matches, in every way that matters, the weld that was tested and proven.
Essential variables
This term comes up constantly and is worth understanding because it explains why qualifications are so narrow. Codes distinguish between variables that meaningfully affect weld properties and those that do not. Change an essential variable beyond the permitted range and the qualification no longer covers the work — requalification is required.
Typically these include the welding process itself, the base material group, filler classification, thickness beyond a defined range, position, and requirements around preheat and post-weld heat treatment. The exact lists and the permitted ranges are defined in the applicable code, and they differ between codes — which is why someone qualified under one standard may still need testing under another.
How the testing process works
- Identify the code and the work. Structural steel, pipe and pressure equipment are governed by different standards with different requirements.
- Find an accredited testing facility. Technical colleges, independent test labs and some employers hold the accreditation to test and certify.
- Weld the test coupon to the specified procedure, in the specified position, under observation.
- The coupon is examined by the method the code requires — commonly visual inspection followed by mechanical testing such as bend tests, or a non-destructive method such as radiography, depending on the standard.
- Results are recorded and, if the coupon passes, the qualification is issued with its scope of coverage stated.
- Continuity is maintained by using the process within the intervals the code requires, with records kept accordingly.
The single most useful thing a prospective candidate can do is contact an accredited facility early and describe the work they intend to do. Testing to the wrong standard is an expensive way to end up with a certificate that does not cover the job you wanted.
Does any of this apply to a home shop
Formally, usually not. Certification exists so that a third party — an inspector, a client, a regulator — can rely on a weld without watching it being made. Building a cart, a gate or a workbench in your own garage does not involve that chain of assurance.
Two things from the certified world are worth borrowing anyway. The first is the habit of writing down what worked: process, material, thickness, filler, gas, settings, position. That is an informal WPS, and it turns a good result into a repeatable one. The second is destructive testing on scrap — bend and break your practice coupons and look at the fracture surface. It is the only way to see whether a weld that looks acceptable actually fused.
A basic fillet weld gauge set is the cheapest way to start assessing your own work against something other than opinion — leg length, throat and profile become measurable rather than a matter of taste. It is also a useful introduction to what an inspector is actually looking at.
Frequently asked questions
What does it mean to be a certified welder?
It means a welder has demonstrated, under observation, that they can produce sound welds using a specific process, on a specific material and thickness range, in a specific position, in accordance with a written procedure — and that the resulting test coupon passed the required examination. It is a qualification tied to those variables, not a general licence to weld anything.
What is the difference between a WPS and a PQR?
A Welding Procedure Specification is the written instruction: the process, material, filler, gas, current, position, preheat and technique for making a particular weld. A Procedure Qualification Record is the evidence that a procedure of that description was actually welded and tested, with the results recorded. In simple terms, the PQR is the proof and the WPS is the instruction the proof supports.
What is a WPQR or welder qualification record?
It records that a particular welder was tested to a particular procedure and passed. The PQR qualifies the procedure; the welder qualification record qualifies the person. Both exist because a sound weld requires a sound procedure and someone able to execute it.
What do 1G, 2G, 3G, 4G, 5G and 6G mean?
They are test position codes. G denotes a groove weld and F a fillet weld. Broadly, 1 is flat, 2 is horizontal, 3 is vertical and 4 is overhead. 5G and 6G apply to pipe: 5G is a fixed horizontal pipe requiring the welder to work around it, and 6G is a fixed pipe at an inclined angle, combining several positions in one test. Qualifying in a harder position generally covers easier ones, within the rules of the applicable code.
Why is 6G considered the hardest test?
Because the pipe is fixed at an angle and cannot be rotated, so the welder must work through flat, vertical and overhead positions continuously around the joint while maintaining consistent penetration and profile. It demands positional control that few other tests require in a single coupon, which is why it carries the reputation it does.
How long does welder certification last?
Continuity requirements vary by code and by employer, but the general principle is that qualification lapses if the welder does not use the process within a defined period, and it can be revoked if work quality gives reason to question it. Many employers require periodic re-testing regardless. Check the specific code and the certifying body rather than assuming a fixed interval.
Do I need certification to weld at home?
No. Certification exists for work where a third party needs documented assurance that a weld meets a standard — structural steel, pipe, pressure equipment, and similar. Personal projects on your own property generally do not require it, though anything structural, load-bearing or life-safety related should be designed and executed by someone qualified regardless of what regulation requires.
How do I get certified?
Through an accredited testing facility, a technical college with a testing programme, or an employer with in-house qualification capability. You weld a test coupon to a specified procedure under observation, and the coupon is examined by the required method. The route and the exact requirements depend on the code you are qualifying to, so start by contacting an accredited facility and telling them what work you intend to do.