Where does AWS D1.1 define which base metals are prequalified?

AWS D1.1:2025 lists approved base metals for prequalified use in a table within Chapter 3 (Base Metal). The table groups structural steels by yield strength range. Always consult the published code table directly rather than relying on memory or third-party summaries.

Why is A514 not on the prequalified base metal list?

A514 is a quenched-and-tempered, high-strength structural steel with a minimum yield of 90 ksi (100 ksi for thinner sections). The microstructure is heat-treatment-sensitive, and preheat, interpass, and heat input must be tightly controlled to avoid HAZ softening and hydrogen cracking. AWS D1.1 requires a PQR for A514 because the prescriptive prequalified limits are insufficient to guarantee weld integrity at that strength level.

If a base metal is on the approved list, can I use any filler metal?

No. The prequalified route also requires the filler metal to be listed and matched to the base metal group. AWS D1.1 Annex I provides a matching and undermatching filler guide. Mismatching filler — even with an approved base metal — disqualifies the prequalified WPS.

What happens if I use an unlisted base metal and proceed without a PQR?

The WPS has no valid supporting qualification. If an inspector or AHJ discovers the issue, the welds may be rejected, requiring repair, additional testing, or complete removal. The liability falls on the contractor.

Prequalified base metals under AWS D1.1:2025: the approved list

AWS D1.1:2025 restricts prequalified WPS use to an approved base metal list. Steels outside that list need a PQR. Here's which grades qualify and why A514 doesn't.

The prequalified WPS route in AWS D1.1 is one of the most powerful cost tools available to a structural steel shop — no test weld required, no PQR costs, no lab fees. But the route comes with a hard gating condition: the base metal must appear on the approved list in the published code. Use a steel that isn't listed and the prequalified path is closed, regardless of how common the metal is or how many times your shop has welded it.

What "prequalified" actually means

A prequalified WPS meets all the prescriptive requirements of AWS D1.1:2025 Clause 5. The code permits this class of WPS to be used without a supporting PQR because the process parameters fall within ranges that the AWS technical committee determined, based on accumulated qualification data, to reliably produce sound welds. The tradeoff is that Clause 5 is prescriptive: joint geometry, filler classification, preheat, heat input, and base metal must all fall within specified limits.

The approved base metal list is one of those limits. AWS D1.1:2025 includes a table in Chapter 3 listing structural steels approved for prequalified WPS use. The list covers the most common structural grades and groups them by mechanical property range. To use the prequalified route, the base metal specification and grade must appear in that table.

Common steels on the approved list

AWS D1.1 has approved for prequalified use a broad set of common structural steels. The following grades have historically appeared on this list and remain there through the 2025 edition (verify against the published code table):

ASTM A36 — the workhorse mild structural steel, 36 ksi minimum yield. Covers most plate, bar, and structural shape applications.

ASTM A572 — high-strength low-alloy (HSLA), Grades 42, 50, 55, 60, and 65. Grade 50 is the dominant grade in wide-flange sections. All grades are approved.

ASTM A588 — weathering steel, 50 ksi minimum yield. Used in exposed structures and bridge applications.

ASTM A992 — wide-flange structural steel, 50 ksi minimum and 65 ksi maximum yield, with yield-to-tensile ratio capped at 0.85. The standard specification for W-sections in seismic and moment frame design.

ASTM A913 — quenched and self-tempered (QST) structural steel, Grades 50, 65, 70, and 80. Grade 65 and Grade 70 are commonly used for heavy W-sections in high-rise construction. See also the dedicated A913 WPS article.

ASTM A53 Grade B and A106 Grade B — used for structural tubing, pipe columns, and hollow structural sections in pipe form.

ASTM A500, A501 — hollow structural sections (HSS). Standard for rectangular and round HSS used in trusses, braces, and moment connections. See the tubular HSS weld procedure article for HSS-specific WPS considerations.

ASTM A1011 and A1018 — sheet and light plate. Approved for structural applications in the lower yield ranges.

This list is not exhaustive — AWS D1.1:2025 includes additional grades, and the table is the governing reference. The point is that virtually every steel a standard structural shop encounters for new construction is on the list.

Steels that are NOT approved: the most important case

ASTM A514 and A517 are not on the approved base metal list. These are quenched-and-tempered (Q&T) steels with minimum yield strengths of 90 ksi (plates over 2.5 in) to 100 ksi (plates 2.5 in and under). They are used in crane booms, heavy equipment, bridges, and pressure vessel applications where weight is critical.

Welding A514 requires a qualified PQR because:

The HAZ of Q&T steel is vulnerable to softening if heat input exceeds the tightly controlled range. Prescriptive prequalified limits are not tight enough to guarantee HAZ integrity.
Hydrogen cracking risk is elevated. The combination of high-strength HAZ, constraint from thick sections, and even modest diffusible hydrogen from the electrode can cause delayed cracking hours or days after welding.
Preheat, interpass, and postweld cooling requirements must be verified experimentally, not assumed from a code table.

A full A514 WPS discussion covers the qualification and parameter requirements in detail.

Other steels that fall outside the approved list include most foreign grades (EN, JIS, CSA grades not specifically listed), proprietary grades without a recognized ASTM designation, and some older grades no longer in common production.

Filler metal must also be listed and matched

Base metal approval is necessary but not sufficient. The prequalified route requires the filler metal to be:

Classified under an applicable AWS A-specification (A5.1, A5.5, A5.18, A5.20, A5.23, A5.28, A5.29, or A5.36 depending on process)
Matched or undermatch to the base metal group per the guidance in AWS D1.1:2025 Annex I

The matching requirement is stricter for higher-strength groups. For A572 Grade 65 or A913 Grade 70, the filler selection must be reviewed carefully — common E70 or ER70S-3 fillers are typically adequate for Grade 50, but Grade 65 and above may require higher-strength consumables.

Using an approved base metal with an improperly matched filler disqualifies the prequalified status, even if all other Clause 5 parameters are met.

The limits that cut across all base metals

Even for steels on the approved list, the prequalified WPS option closes if the application parameters exceed Clause 5 prescriptive limits:

Thickness limits. Clause 5 specifies geometry and throat size limits. Very thick sections (particularly T-joints and complete joint penetration welds in heavy sections) may not be coverable under the prequalified geometry tables.

Joint geometry. Only joint configurations specifically listed in Clause 5 (and illustrated in the applicable figures) qualify. Custom joint geometries or modified root openings outside the listed range require a PQR.

Welding process. Not all processes are prequalified. Electroslag (ESW) and electrogas (EGW) welding require a PQR — there is no prequalified route for these processes, regardless of the base metal.

Making the prequalified/PQR decision

For most structural shops working with A36, A572 Grade 50, and A992, the prequalified route is straightforward and cost-effective. The cost comparison between prequalified and PQR-backed WPSs shows why most shops lean prequalified for common applications.

The decision gets more nuanced for mixed-material jobs where some base metals are on the approved list and others aren't. A single job with A572 Grade 50 wide-flanges and A514 crane runway beams requires two separate qualification approaches. The A572 can go prequalified; the A514 needs a PQR.

Rule library based on AWS D1.1:2025; verify against your governing edition. The approved base metal table in the published code is the authoritative reference — do not rely on any third-party summary, including this one, for final qualification decisions.

For shops managing WPS qualification across multiple steel grades and heat levels, see the pricing page for software plan options.