Does a WPS need to list wire feed speed or just amperage?

For GMAW and FCAW, AWS D1.1 requires the WPS to specify the current (amperage) range. Wire feed speed is closely related and many shops document both, but amperage is the essential variable parameter. Wire feed speed can be listed as a supplemental reference parameter to help production welders set up consistently.

Is wire feed speed an essential variable under AWS D1.1:2025 Table 6.6?

Amperage (welding current) is the essential variable — not wire feed speed directly. However, for a given electrode diameter and alloy, WFS and amperage have a predictable relationship. Changing WFS substantially changes amperage, which can move the WPS outside its qualified amperage range.

If a welder adjusts wire feed speed during production, is that a WPS violation?

It depends on whether the resulting amperage falls outside the range specified on the WPS and qualified by the PQR. If the adjusted WFS keeps amperage within the documented range, no violation. If it pushes amperage outside the range, that's an essential variable exceedance requiring requalification or a new PQR.

What's the amperage qualification range for GMAW under AWS D1.1?

AWS D1.1:2025 Table 6.6 specifies the allowable variation in amperage (and voltage) for GMAW. The PQR records the tested parameters, and the production WPS must fall within the qualified range. Consult Table 6.6 directly for the exact percentage or absolute limits — do not rely on memory.

Jun 12, 20265 min read

Wire feed speed vs. amperage on a GMAW and FCAW WPS

For GMAW and FCAW, amperage and wire feed speed are interrelated but not interchangeable on a WPS. Here's what AWS D1.1:2025 requires you to document and why WFS matters for essential variable compliance.

WPS GMAW FCAW Essential Variables AWS D1.1 Table 6.6

New to procedures? Start with WPS welding: what a welding procedure specification is, with a filled-in example.

Walk through a typical GMAW or FCAW WPS and you'll find a row for amperage, another for voltage, and often a row for wire feed speed (WFS). These parameters are listed side by side but they're not equivalent. Understanding the relationship between WFS and amperage — and which one controls essential variable compliance — prevents a common setup mistake that shows up in both production and audits.

What's on a GMAW/FCAW WPS

A properly written GMAW or FCAW WPS will document, at minimum:

Electrode classification and diameter
Shielding gas type and flow rate (GMAW)
Amperage range (minimum and maximum)
Voltage range (minimum and maximum)
Travel speed range
Contact tip-to-work distance (CTWD) or electrode extension range
Welding position and progression

Wire feed speed often appears alongside amperage, either in its own field or as a reference note. Some shops document WFS as the primary setup parameter for the welder — it's what they dial in on the machine — while amperage is what the inspector or QC manager verifies against the WPS range.

Why WFS and amperage are tied together

For constant-voltage (CV) power sources — the standard for GMAW and FCAW — wire feed speed and amperage are directly related for a given electrode diameter, alloy, and contact tip-to-work distance. Increase WFS and the machine draws more current to maintain arc length. Decrease WFS and current drops.

This relationship is why experienced welders use WFS as their primary setup control. The machine self-regulates voltage across a narrow band once set, and WFS dialing gets the amperage into the right range. But the relationship is not perfectly linear across all CTWD values, and it shifts with electrode diameter and alloy.

On the WPS, amperage is the parameter that matters for essential variable compliance. WFS is a means to that end.

What AWS D1.1:2025 Table 6.6 actually requires

AWS D1.1:2025 Table 6.6 — the essential variable table for SMAW, SAW, GMAW, FCAW, and GTAW — specifies amperage (welding current) and voltage as essential variables. The table defines allowable variation limits around the PQR-tested values. Exceeding those limits requires a new or revised PQR.

Wire feed speed is not independently listed as an essential variable in Table 6.6, but because it directly drives amperage for CV processes, a WFS change that pushes amperage outside the Table 6.6 range is still an essential variable violation — just one step removed.

Rule library based on AWS D1.1:2025; verify against your governing edition.

The production setup problem

Here's where things go wrong in production: the WPS specifies an amperage range of, say, 180–220 A for a given pass. A welder sets up using WFS and achieves 195 A — within range. Later, without thinking about it, they bump the WFS dial to get a better bead profile or to fill a gap faster. Now amperage climbs to 240 A. The WPS says 220 A max. No one checks because the weld looks fine.

This is a routine finding during production-record audits and third-party QC surveillance. The weld may be structurally sound — the overage is often minor — but the WPS was violated. If the deviation is not documented, the record is inaccurate. If it was documented and the cause was WFS adjustment, that's the root cause for corrective action.

For FCAW-S (self-shielded flux-cored), WFS control is especially important because the process is sensitive to voltage and current interaction. Running outside the WPS parameters on FCAW-S affects deposition and shielding characteristics more than on shielded processes.

How to document WFS on the WPS form

Best practice: document both amperage range and the corresponding WFS range. The WFS range gives production welders a dial target; the amperage range is the QC-verifiable essential variable parameter.

Example entry:

Amperage: 180–220 A
Wire Feed Speed: 280–340 in/min (reference — verify amperage)
Electrode: E71T-1C, 0.045 in diameter
CTWD: 3/4 in [19 mm]

Label WFS as "reference" if your form uses a formal distinction between essential and non-essential parameters. This avoids confusion if a third party reads the WPS and wonders why WFS isn't explicitly listed in Table 6.6.

If you use the Annex J WPS form, fill in the amperage/voltage fields with the qualified ranges. Add WFS as a note in the remarks or supplemental parameters section.

Electrode diameter interacts with WFS-to-amperage conversion

Changing electrode diameter is an essential variable under Table 6.6. One reason is that a given WFS produces very different amperage at different wire diameters. A 0.035 in wire at 300 in/min produces significantly lower current than 0.045 in wire at the same WFS. If your WPS was qualified with 0.045 in wire and someone switches to 0.035 in — perhaps to improve out-of-position performance — the entire WFS-to-amperage relationship shifts. The WPS is now unsupported by its PQR.

This interaction means that electrode diameter on the WPS is not just a filler metal call — it's tied to the entire amperage and WFS envelope the PQR established.

Practical checklist for GMAW/FCAW WPS amperage documentation

When writing or reviewing a GMAW or FCAW WPS:

Record PQR amperage and voltage as measured during the test coupon — use actual weld monitor data, not the machine preset.
Set the production WPS range within the Table 6.6 limits around the PQR-tested values.
Add the corresponding WFS range as a reference parameter, computed from the tested electrode at the CTWD used in the PQR.
Note electrode diameter — it determines the WFS-to-amperage conversion curve.
Check the WPS shielding gas — for GMAW, a gas change is an essential variable that can affect arc behavior and the WFS-to-amperage relationship. See GMAW shielding gas change and WPS requalification for detail.

For FCAW-G (gas-shielded flux-cored), treat the WFS and amperage relationship the same as GMAW. For FCAW-S (self-shielded), follow the same essential variable rules but be aware the process is more sensitive to parameter drift.

For a walkthrough of essential variables across all processes, see AWS D1.1:2025 Table 6.6 explained and WPS essential variables vs. nonessential. Managing GMAW and FCAW WPS parameter ranges with automatic essential-variable checking is available through our WPS software.

FAQ

Frequently asked.

Does a WPS need to list wire feed speed or just amperage?: For GMAW and FCAW, AWS D1.1 requires the WPS to specify the current (amperage) range. Wire feed speed is closely related and many shops document both, but amperage is the essential variable parameter. Wire feed speed can be listed as a supplemental reference parameter to help production welders set up consistently.
Is wire feed speed an essential variable under AWS D1.1:2025 Table 6.6?: Amperage (welding current) is the essential variable — not wire feed speed directly. However, for a given electrode diameter and alloy, WFS and amperage have a predictable relationship. Changing WFS substantially changes amperage, which can move the WPS outside its qualified amperage range.
If a welder adjusts wire feed speed during production, is that a WPS violation?: It depends on whether the resulting amperage falls outside the range specified on the WPS and qualified by the PQR. If the adjusted WFS keeps amperage within the documented range, no violation. If it pushes amperage outside the range, that's an essential variable exceedance requiring requalification or a new PQR.
What's the amperage qualification range for GMAW under AWS D1.1?: AWS D1.1:2025 Table 6.6 specifies the allowable variation in amperage (and voltage) for GMAW. The PQR records the tested parameters, and the production WPS must fall within the qualified range. Consult Table 6.6 directly for the exact percentage or absolute limits — do not rely on memory.