Base metal · AWS D1.1 Table 5.6

ASTM A36 WPS: check the thickness before using Group I

AWS D1.1/D1.1M:2025 Table 5.6 lists A36 in Group I only through 3/4 in. (20 mm), and also lists A36 in Group II for all thicknesses. That distinction changes the available filler-metal matching group; it does not decide full WPS eligibility.

Practical check: for A36 thicker than 3/4 in. (20 mm), do not use the Group I A36 entry to justify filler matching. The Table 5.6 Group II entry remains available at all thicknesses. Use the code's own SI or U.S. customary column as applicable; do not convert one cutoff into a different threshold.

A36's two Table 5.6 entries

Table 5.6 group	A36 listing	What this establishes
I	Thickness ≤3/4 in. or 20 mm	Group I may be used for the Table 5.7 filler matching check within the stated thickness limit.
II	All thicknesses	Group II is listed for A36 at all thicknesses for the filler matching check.

Example: an A36 member at 1 in. (25 mm) is beyond the Group I entry. The Group II entry is the supported Table 5.6 group for that member. This is a material-group answer only; it does not select a filler product, approve the joint, or establish Clause 5 eligibility.

Keep filler group and preheat category separate

Table 5.6 Groups I and II are strength groups used for filler-metal matching under Table 5.7. They are not the lettered temperature categories in Table 5.11. A36 is listed in preheat Category A for SMAW with non-low-hydrogen electrodes and Category B for low-hydrogen SMAW, SAW, GMAW or FCAW. The selected process and applicable project limits determine which path to check.

For example, for a 25 mm A36 joint using GMAW, the Table 5.11 Category B SI step is 10°C. The 25 mm member still uses Group II for the Table 5.6 matching check. These are two separate table decisions; actual preheat may be higher when another applicable requirement controls.

Look up a listed base metal Check filler matching families Compare preheat inputs

What this A36 check does not establish

Table 5.6 listing alone does not make a WPS prequalified. Check all applicable Clause 5 conditions, including the other base metal and combination, process sequence, filler classification, joint details, position, thickness coverage and temperature requirements.
A Table 5.7 classification family is not product approval. Check the complete classification and product-specific position, size, gas, operating range and project requirements.
For an existing-PQR route, use the actual PQR record and applicable qualification coverage; do not infer PQR coverage from the Table 5.6 group.
Verify the material specification and grade from project records. “A36” must not be assumed from a generic carbon-steel description.

Review known prequalified-route gates Compare prequalified and PQR routes

Edition and source

Material-group facts: AWS D1.1/D1.1M:2025 Table 5.6, printed pages 73–76. Preheat categories and temperature steps: Table 5.11, printed pages 81–84. Filler matching: Table 5.7. This guide reflects the base edition plus registered base-edition errata dated July 28, 2026; AMD1 is not included. The contract edition governs the project.

See the full code-basis statement and other material guides.

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