What is a welding procedure specification (WPS)?

A WPS is the written instruction that tells a welder exactly how to make a particular weld: the process, base metals and thickness range, filler metal, joint detail, position, preheat and interpass temperatures, shielding, electrical parameters, and technique. It exists so the same joint is welded the same way by anyone, and so an inspector can check the work against a stated set of conditions.

What is a procedure qualification record (PQR)?

A PQR is the record of a test weld made to a candidate procedure, listing the values actually used and the results of the mechanical tests performed on the coupon. It is the objective evidence that welding within those ranges produces a sound joint. A PQR is never revised — if conditions change beyond the qualified range, a new test produces a new PQR.

What is the difference between a WPS and a PQR?

The WPS is the forward-looking instruction used in production; the PQR is the backward-looking proof that the instruction works. One WPS may be supported by one or more PQRs, and a single PQR can support several WPSs whose variables fall inside the qualified ranges.

Does every WPS need a PQR?

No. Where the applicable welding code allows a prequalified procedure — common combinations of process, filler metal and joint detail within stated limits — the WPS can be written as prequalified and needs no supporting qualification test. Anything outside those limits must be qualified by test, and then the PQR is required.

How long do you keep WPS and PQR records?

PQRs are normally retained for as long as any WPS relies on them, and superseded WPS revisions are kept for the retention period stated in your own quality manual and for as long as any contract or specification demands. Auditors ask for the retention rule first, then sample against it.

Who is allowed to write and approve a WPS?

Writing is usually done by a welding engineer or a qualified welding coordinator; approval is by whoever your quality manual names as the approving authority. What matters for an audit is that the manual states who approves procedures and that the signatures on the sheets match it.

WPS vs PQR — plus a free WPS form template

A welding procedure specification tells a welder how to make a weld. A procedure qualification record proves that instruction produces a sound joint. Confusing the two is the most common welding-documentation finding in a fabrication shop. Below: how they differ, a printable WPS form you can use today, and guidance on every field so the sheets come out consistent.

Manage these in SteelQMS

This template is an original SteelQMS layout, not text from any welding code or standard — those are copyrighted. Check it against the code your work is contracted to, and adapt it to your own quality manual before use. SteelQMS is not affiliated with, endorsed by, or sponsored by AISC or AWS.

WPS vs PQR at a glance

WPS

PQR

What it is

WPS: The written instruction telling a welder how to make a specific weld.

PQR: The record of a test weld and its results, proving the instruction produces a sound joint.

Who uses it

WPS: Welders and inspectors, at the bay, while the work happens.

PQR: Quality and engineering, as supporting evidence behind the WPS.

Contains

WPS: Process, base metals, filler, position, joint detail, preheat, electrical parameters, technique.

PQR: The as-welded values actually used, plus mechanical test results and who witnessed them.

Changes when

WPS: Any essential variable moves outside the qualified range — a new revision is issued.

PQR: Never. A PQR is a historical record; a new test produces a new PQR.

Needed to weld?

WPS: Yes — welding to an unwritten or withdrawn procedure is a finding.

PQR: Only when the WPS is not prequalified; prequalified procedures need no supporting PQR.

The WPS form

Controlled document

Welding Procedure Specification

Company: ______________________

Prequalified: ☐ Yes ☐ No (PQR attached)

WPS number
Revision / date
Supporting PQR number
Welding process(es)
Base metal specification and group
Joint type and detail
Filler metal classification
Positions qualified
Preheat and interpass temperature
Shielding gas or flux
Electrical characteristics
Technique
Postweld heat treatment
Prepared by / date
Approved by / date

Attach the joint sketch and, where the procedure is qualified by test, the supporting procedure qualification record. Retain superseded revisions per your quality manual’s record-retention rule.

How to fill in each field

WPS number: Unique and stable, e.g. WPS-FCAW-01 — welders will cite it on logs
Revision / date: Bump the revision whenever an essential variable changes
Supporting PQR number: Leave blank only if the procedure is prequalified; say which
Welding process(es): SMAW, FCAW, GMAW, GTAW, SAW — and whether semi-automatic or automatic
Base metal specification and group: Material spec and thickness range the procedure covers
Joint type and detail: Groove or fillet, root opening, groove angle, backing, sketch attached
Filler metal classification: AWS classification, diameter, and trade name if controlled
Positions qualified: Flat, horizontal, vertical, overhead — or the 1G–4F designations
Preheat and interpass temperature: Minimum preheat and maximum interpass, with how it is measured
Shielding gas or flux: Composition and flow rate, or flux classification for SAW
Electrical characteristics: Current type and polarity, amperage, voltage and travel-speed ranges per pass
Technique: Stringer or weave, number of passes, cleaning between passes, back-gouging, peening restrictions
Postweld heat treatment: Temperature, hold time and cooling rate, or a clear statement that none is required
Prepared by / date: The person who wrote the procedure
Approved by / date: The authority named in your quality manual as approving procedures

Keeping procedures controlled

Writing the sheet is the easy half. Process-control and document-control expectations in AISC 207-25 (§1.12.1, §1.8) come down to whether the current procedure is available where the welding happens and whether the evidence behind it is retrievable.

A WPS that is not prequalified is only valid while a PQR supports it — link the two in the register so the pair travels together.
Keep superseded revisions retrievable but clearly marked, so nobody welds to a withdrawn sheet pinned to a bay wall.
The current revision has to be available where the welding happens, not only in the quality office.
Welder qualifications are separate records: the WPS qualifies the procedure, the welder test qualifies the person.
Weld logs should cite the WPS number, giving the traceability chain from a finished weld to procedure and welder.

Questions fabricators ask about WPS and PQR

What is a welding procedure specification (WPS)?: A WPS is the written instruction that tells a welder exactly how to make a particular weld: the process, base metals and thickness range, filler metal, joint detail, position, preheat and interpass temperatures, shielding, electrical parameters, and technique. It exists so the same joint is welded the same way by anyone, and so an inspector can check the work against a stated set of conditions.
What is a procedure qualification record (PQR)?: A PQR is the record of a test weld made to a candidate procedure, listing the values actually used and the results of the mechanical tests performed on the coupon. It is the objective evidence that welding within those ranges produces a sound joint. A PQR is never revised — if conditions change beyond the qualified range, a new test produces a new PQR.
What is the difference between a WPS and a PQR?: The WPS is the forward-looking instruction used in production; the PQR is the backward-looking proof that the instruction works. One WPS may be supported by one or more PQRs, and a single PQR can support several WPSs whose variables fall inside the qualified ranges.
Does every WPS need a PQR?: No. Where the applicable welding code allows a prequalified procedure — common combinations of process, filler metal and joint detail within stated limits — the WPS can be written as prequalified and needs no supporting qualification test. Anything outside those limits must be qualified by test, and then the PQR is required.
How long do you keep WPS and PQR records?: PQRs are normally retained for as long as any WPS relies on them, and superseded WPS revisions are kept for the retention period stated in your own quality manual and for as long as any contract or specification demands. Auditors ask for the retention rule first, then sample against it.
Who is allowed to write and approve a WPS?: Writing is usually done by a welding engineer or a qualified welding coordinator; approval is by whoever your quality manual names as the approving authority. What matters for an audit is that the manual states who approves procedures and that the signatures on the sheets match it.

Or keep the register instead of the paperwork

SteelQMS holds every WPS with its revision history and supporting PQR, shows which process and position combinations you actually have covered, and ties each logged weld to the procedure and welder that produced it — with welder continuity advancing automatically as welds are logged.

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