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.

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.

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.

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.