AWS A2.4 §7 · D1.1:2025 Figure 5.1
Groove Weld Symbol
All 11 開先溶接 種類 per AWS A2.4. How to read CJP vs PJP from the symbol, dimension placement rules, and D1.1:2025 事前認定 joint details.
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Groove Weld Types — Overview
V-Groove
Bevel
Square
J-Groove
CJP vs PJP: No dimensions on a groove symbol = CJP (full penetration). A 溶接サイズ (S) in parentheses to the left = PJP (partial penetration). The parentheses are the 目視 signal.
A2.4 Figures 7.1, 7.2, 7.6, 7.19
Groove Weld Application Diagrams
These diagrams show how groove weld dimensions are placed on the symbol and how they correspond to the actual joint cross-section.
Fig 7.1(D) — CJP, no dimensions
Fig 7.1(F) — PJP, weld サイズ in parens
Fig 7.2 — Combined dimensions
Fig 7.6 — Groove + fillet combo
Fig 7.19 — Backgouging sequence
Dimension Rules
Where Each Dimension Goes
Per AWS A2.4 §7, all groove weld dimensions appear on the same side of the reference line as the 溶接記号.
| Dimension | Location | CJP/PJP |
|---|---|---|
| D (groove depth) | To the LEFT of the symbol, no parentheses | PJP only — omitted for CJP |
| (S) (weld size) | To the LEFT, in parentheses | PJP only — omitted for CJP |
| R (ルート間隙) | INSIDE the symbol | Both CJP and PJP |
| α (開先角度) | ABOVE or BELOW the symbol (per A2.4 §7.3.2) | Both CJP and PJP |
| Length | To the RIGHT of the symbol | Both CJP and PJP |
Common confusion: D (groove depth) and (S) (weld size) are not the same thing. D is how deep you cut the groove. (S) is the effective weld throat for 強度 calculations. For many joints, D ≥ S. The number without parentheses is D; with parentheses is (S).
All 11 Types
Groove 溶接の種類 Reference
| D1.1 Type | Name | Symbol Shape |
|---|---|---|
| 1 | Square groove | Two parallel vertical lines |
| 2 | Single-V groove | V-shape (symmetric) |
| 3 | Double-V groove | X-shape (V on both sides) |
| 4 | Single-bevel groove | One vertical + one angled line |
| 5 | Double-bevel groove | K-shape |
| 6 | Single-U groove | U-shape (curved bottom) |
| 7 | Double-U groove | Two U-shapes back to back |
| 8 | Single-J groove | One vertical + one J-curve |
| 9 | Double-J groove | Two J-shapes |
| 10 | Flare-bevel groove | One curved + one vertical line |
| 11 | Flare-V groove | Two curved lines |
Note: The edge weld symbol is classified separately from groove welds under A2.4 条項 13.
D1.1:2025
Prequalified Joint Details
D1.1:2025 organizes prequalified groove weld joints into figures. These joints have been tested and approved — using one means you can write a WPS directly without running qualification tests.
| Figure | Content | Key Detail |
|---|---|---|
| Figure 5.1 | Prequalified CJP groove welded joint details | Types 1-9, all processes, all positions |
| Figure 5.2 | Prequalified PJP groove welded joint details | As Detailed + As Fit-Up tolerances |
| Figure 5.3 | Prequalified すみ肉溶接 joint details | Not groove — see fillet page |
| Figure 5.4 | Prequalified skewed T継手 details | Dihedral angles 60°–135° |
Joint designation: Each prequalified joint has a designation like B-U2a (butt, unlimited 板厚, single-V, with バッキング). This designation must appear on the WPS — “single-V groove 突合せ継手” alone is not sufficient.
Because CJP groove welds carry the full design load across the joint, each configuration typically requires the test record that proves a 溶接施工法 works — a qualification test on a sample joint before production 溶接 begins. The tested parameters are then locked into a written welding procedure that governs every production weld.
"Complete joint penetration groove welds are the only weld type that develops the full strength of the connected members. D1.1 Clause 5.4.1 and Figure 5.1 prequalify specific groove geometries — V, bevel, U, J, and flare — so that CJP can be achieved without 手順資格 試験, provided the WPS stays within the 継手詳細 parameters."
— D1.1:2025 Clause 5.4.1 and Figure 5.1, Prequalified CJP Groove Welded Joint Details
Groove Weld Configurations — A2.4 Figures 7.1–7.19
CJP — no dimensions per §7.2.2
PJP — D and (S) per §7.2.6
Root opening — R per §7.3.1
Groove angle — per §7.3.2
Combined groove+fillet — Fig 7.6
Backgouging — Fig 7.19, §7.11
CJP vs PJP rule (A2.4 §7.2.2): No groove depth and no weld size on the symbol = CJP (full penetration). A number in parentheses (S) = PJP weld size. A number without parentheses = groove depth D. These are not interchangeable — the parentheses are the distinguishing signal.
Common Questions
Groove Weld Symbol FAQ
What is a groove weld symbol?
A groove weld symbol indicates a weld made in a groove between workpieces. AWS A2.4 Figure 4.1 defines 8 groove symbol types: square, V, bevel, U, J, flare-V, flare-bevel, and scarf (brazing only). Each can be applied as single-groove or double-groove to cover the commonly referenced configurations (square, single/double-V, single/double-bevel, single/double-U, single/double-J, flare-V, flare-bevel). The shape of the symbol on the reference line represents the joint preparation geometry. For example, a V-groove weld uses a V-shaped symbol, while a J-groove uses a J-shaped symbol. Groove welds are the primary way to achieve complete joint penetration (CJP) in structural steel. In D1.1:2025, groove welds on moment connections must be CJP per Clause 4.3.2 because they develop the full strength of the connected flanges. The choice of groove type depends on plate thickness, welding position, and access: single-V is common for shop welds, while single-bevel is preferred for field erection where only one side is accessible.
How do you tell CJP from PJP on a groove weld symbol?
The key is parentheses. A CJP groove weld has no groove depth (D) and no weld size (S) specified on the symbol — the weld penetrates the full joint thickness. Alternatively, CJP may appear in the tail of the welding symbol. A PJP groove weld shows the weld size (S) in parentheses to the left of the symbol — e.g. (3/8) means 3/8 in. effective weld size. The parentheses are the visual signal that distinguishes PJP from CJP. If you see a number without parentheses to the left, that is the groove depth D, not the weld size. For example, on a single-bevel symbol: 3/4 (no parentheses) to the left means 3/4 in. groove depth, while (3/8) means 3/8 in. PJP effective throat. This distinction is critical for fabricators sizing their weld joint preparation.
Where do groove weld dimensions go on the symbol?
Per AWS A2.4 §7, all groove weld dimensions go on the same side of the reference line as the weld symbol. Groove depth (D) goes to the left without parentheses. Weld size (S) goes to the left in parentheses. Root opening (R) goes inside the symbol. Groove angle goes above or below the weld symbol as appropriate (A2.4 §7.3.2). For example, a single-V groove weld with 45° groove angle, 1/4 in. root opening, and 5/8 in. effective weld size would show: (5/8) to the left in parentheses (weld size), the V symbol, 1/4 inside the symbol (root opening), and 45 above/below (groove angle per §7.3.2). For CJP, both D and S are omitted because the weld penetrates the full thickness. For double-groove joints, each groove is dimensioned independently on its respective side of the reference line.
What are D1.1 prequalified groove weld joints?
D1.1:2025 Figure 5.1 contains prequalified CJP groove welded joint details — joint configurations that have been tested and approved for use without requiring a separate procedure qualification record (PQR). Each joint has a designation (e.g. B-U2a for a single-V butt joint, TC-U4b for a T-joint with backing), specified groove angle, root opening, root face, and approved welding positions. B-U2a, for example, is one of the most commonly used butt joint details and is approved for SMAW in the flat, vertical, and overhead positions. Figure 5.2 covers prequalified PJP joints. Using a prequalified joint detail per Clause 5.4.1 means you can write a WPS directly from the figure without running qualification tests, saving weeks and thousands of dollars in qualification costs.