Clause 6.11.1(3) · WPS Qualification InheritanceCJP Groove Test Qualifies a Fillet WPS
AWS D1.1:2025 Clause 6.11.1(3) states a qualified CJP groove WPS qualifies all fillet welds regardless of size or base metal thickness, per Table 6.1. The inheritance is one-way: CJP qualifies fillet, fillet does not qualify CJP. Position-matching from the plate test still governs production fillet positions.
The Question Behind the Page
A common shop-floor and AWS forum question: a fabricator has a qualified CJP groove WPS on plate. The next job calls for fillet welds. Does the existing CJP qualification cover the fillet work, or is a separate fillet test required? The question reads as if AWS D1.1 might be silent on it, but the code is direct. The answer lives in Clause 6.11.1, and the rule is one of the most useful one-way inheritances in the code.
Per AWS D1.1:2025
Clause 6.11.1: “Qualification of a CJP groove weld WPS using plate shall qualify the WPS for use in production for the following: ... (3) All fillet welds regardless of size or base metal thickness in accordance with the requirements of Table 6.1.”
Two phrases carry the weight. “Regardless of size or base metal thickness” removes the natural reflex to look for a thickness range or a leg-size cap on the fillet side. “In accordance with the requirements of Table 6.1” pulls position-matching back into the picture, so the inheritance is not unconditional on position, only on size and thickness.
The Inheritance Matrix
AWS D1.1 Clauses 6.11.1, 6.12.1, and 6.13.1 each state what a given WPS test path qualifies. Reading them together gives the one-way structure clearly.
| Test path used to qualify the WPS | CJP groove production | PJP groove production | Fillet production | Plug / slot production |
|---|---|---|---|---|
CJP groove plate test (Clause 6.11) |
Yes (Tables 6.1, 6.2) | Yes (Clause 6.12.3, Tables 6.1, 6.3) | Yes — any size, any thickness (Table 6.1) | Yes — in tested position |
PJP groove plate test (Clause 6.12) |
No | Yes (Tables 6.1, 6.3) | Yes — any size, any thickness (Table 6.1) | Yes — in tested position |
Fillet plate T-test (Clause 6.13) |
No | No | Yes (Tables 6.1, 6.4) | Yes — in tested position |
Read top-down: the CJP groove test is the most demanding qualification path in Clause 6 and earns the broadest coverage. The PJP test is in the middle. The fillet test is the narrowest. Read left-to-right: fillet welds and plug or slot welds appear in every row because they sit below groove welds on the inheritance ladder. Groove welds only appear in their own rows, because the lighter tests do not confirm penetration behavior at depth.
The Thickness Side of the CJP Test
The CJP groove qualification is governed on the thickness side by Table 6.2. Three plate-thickness bands set the qualified production-thickness range for groove production. The fillet inheritance from Clause 6.11.1(3) is separate from these limits and has no upper bound on the fillet side, but the groove-thickness band you tested at still affects what CJP and PJP production weld thicknesses you can run.
| Nominal plate thickness T tested, in [mm] | Min. qualified base metal thickness | Max. qualified base metal thickness |
|---|---|---|
| 1/8 ≤ T ≤ 3/8 [3 ≤ T ≤ 10] | 1/8 [3] | 2T |
| 3/8 < T < 1 [10 < T < 25] | 1/8 [3] | 2T |
| 1 and over [25 and over] | 1/8 [3] | Unlimited |
The unlimited row is the reason many shops choose to qualify at one inch or thicker even when current production work is lighter. It buys the full groove-production range on top of the unconditional fillet inheritance.
The Position Side of the Inheritance
The fillet inheritance from Clause 6.11.1(3) defers to Table 6.1 for position. A 1G plate test qualifies flat (1F fillet). A 2G test adds horizontal (1F + 2F = F, H). A 3G test adds vertical (V). A 4G test adds overhead (OH). The position discipline is the same as for groove production. The fact that the size and thickness restrictions disappear on the fillet side does not mean the position restrictions disappear too.
A typical production plan is to qualify in 3G and 4G plates if vertical and overhead fillet positions will be needed. That covers most production cases without paying for a separate fillet test, while keeping the full groove inheritance from Clause 6.11.1.
Three Common Misreadings
Treating the inheritance as symmetric. A fillet test does not qualify a groove WPS. Clause 6.13.1 stops at all fillet welds and plug or slot welds in the qualified position. If a shop has only run a fillet T-test and gets a CJP groove job, a new qualification test is required.
Reading a fillet thickness limit into the CJP inheritance. Clause 6.11.1(3) says “regardless of size or base metal thickness.” The thickness limits in Table 6.2 apply to the groove side, not to the fillet side of the same qualified WPS. A 3/8-inch CJP groove test still qualifies fillet welds on plate over 1 inch thick.
Assuming WPS coverage means welder coverage. The Clause 6.11.1(3) inheritance is a WPS-level statement. Welder and welding-operator qualification is governed by Clause 6, Part C, with its own positions table (Table 6.11) and its own inheritance rules. A qualified WPS does not by itself qualify the people running it.
What Buys the Inheritance: Tests Required by Clause 6.11.3
The reason the CJP test path earns the broad downstream coverage is that the tests required are the most demanding in Clause 6. Clause 6.11.3 lists them: visual inspection of the completed test coupon, NDT of the completed test coupon, bend testing of specimens (root or face bends for thinner plate, side bends for thicker plate per Table 6.2), and tensile testing of specimens. Clause 6.13.2 for the fillet test path requires only macroetch of the plate T-test and the consumables verification test. The fillet test path simply does not develop the same level of evidence about penetration behavior, which is why it cannot be used backward to qualify a groove WPS.
Field note: Test once at one inch or thicker, in the harder positions you actually run, and use the Clause 6.11.1 inheritance to absorb most of the lighter work. The repeat cost of qualification tests is the slow drain on a fabrication shop, and the CJP path is the test that pays for itself.
Frequently Asked Questions
Yes. AWS D1.1:2025 Clause 6.11.1(3) states that qualification of a CJP groove weld WPS using plate qualifies the WPS for use in production for all fillet welds regardless of size or base metal thickness in accordance with the requirements of Table 6.1. The rule is unconditional on the fillet side: no thickness floor, no size cap, no second test. Table 6.1 governs which production positions are usable, since position-matching from the plate test (1G, 2G, 3G, 4G) controls which production fillet positions (1F, 2F, 3F, 4F) are qualified. Clause 6.11.1 also extends the same CJP test result to all CJP groove welds (per Tables 6.1 and 6.2), all PJP groove welds (per 6.12 and Tables 6.1 and 6.3), and all plug and slot welds in the position tested. The one-way inheritance is the value the CJP test path buys you.
A CJP groove test is the most demanding plate qualification path in AWS D1.1 Clause 6: full-penetration weld, reduced-section tension tests, root or face bends or side bends, and visual plus NDT acceptance per Clause 6.10. A fillet weld qualification test (Clause 6.13 and Table 6.4) requires only macroetch specimens from a plate T-test plus the consumables verification test, and gives the welder no penetration check at all. The PJP path (Clause 6.12 and Table 6.3) sits between the two. Because the CJP test confirms more about the procedure than either of the other two tests can, AWS D1.1 lets it cover the lighter cases below it. A fillet test does not confirm penetration behavior at depth, so it cannot be used to qualify a CJP or PJP groove WPS. Clause 6.13.1 stops the fillet test at all fillet welds, all plug welds, and all slot welds in the qualified test position.
It depends on the plate thickness in the test coupon. AWS D1.1:2025 Table 6.2 splits the qualified groove thickness range into three bands. A test plate between 1/8 inch and 3/8 inch [3 mm to 10 mm] qualifies base metal from 1/8 inch up to 2T. A test plate above 3/8 inch and below 1 inch [10 mm to 25 mm] also qualifies up to 2T. A test plate at 1 inch [25 mm] or thicker qualifies base metal from 1/8 inch up to unlimited. The unlimited row is the reason many fabricators run the qualification test at 1 inch or thicker: it covers the full production range on the groove side. For ESW and EGW the range is narrower: 0.5T to 1.1T. The fillet inheritance under Clause 6.11.1(3) is separate from these groove thickness limits and has no upper bound.
Yes. AWS D1.1:2025 Table 6.1 lists production positions qualified by the plate test. A 1G CJP groove test qualifies flat production welding only (1F fillet, butt-joint CJP F, T-Y-K connection CJP F). A 2G test adds horizontal (F, H). A 3G test gives vertical (V). A 4G test gives overhead (OH). The fillet inheritance carries the same position discipline: the CJP test does not unlock all production fillet positions at once. If the production fillet detail is overhead and the qualification test was 1G, the fillet WPS is qualified for flat fillets only and the overhead fillet still needs a separate test position. The way most shops handle this is to qualify in 3G and 4G to cover the harder positions, then rely on Table 6.1 footnote a for pipe coverage when applicable.
On the WPS side, none. Once a CJP groove WPS is qualified per Clause 6.11, no separate fillet WPS qualification test is required to start producing fillet welds with the same procedure parameters, regardless of fillet size or base metal thickness, in the qualified positions. Welder and welding-operator qualification is a separate question and is governed by Clause 6, Part C, which has its own positions tables (Table 6.11) and inheritance rules. Visual inspection acceptance criteria for production fillet welds also still apply per Clause 8. The Clause 6.11.1(3) inheritance is specifically a WPS-level statement, not a welder-level statement, and not an inspection-acceptance statement. A common audit miss is to assume the CJP qualification covers everything; it covers the procedure, not the people running it or the production weld acceptance.
Source: AWS D1.1/D1.1M:2025 Clause 6.11.1, Clause 6.12.1, Clause 6.13.1, Table 6.1, Table 6.2, Table 6.4, verified against the local source PDF and extracted corpus.
For reference only — verify against the cited code edition and your project contract documents before production use.