Flare-V Groove Weld Symbol
How to read a flare-V groove weld symbol — Y-shape for two curved surfaces in side-by-side contact. Groove weld size measured from the outside surface. No machining required.
Flare-V Groove Symbol Dimensions
The flare-V groove symbol has two outward-curving lines that look like a Y sitting on the reference line. This represents two curved surfaces (such as round bars or tubes) placed side by side, creating a natural V-shaped groove at their contact line.
What the Joint Looks Like
Per A2.4 §7.2.10.2, a flare-V groove weld joint occurs from the side-by-side longitudinal contact between two curved surfaces. No machining is required — the groove is formed by the member geometry itself. Common examples: two round bars welded side by side, two round HSS sections in contact.
Groove Weld Size (S)
Per A2.4 §7.2.10.5, the groove weld size S is measured from the outside surface of the curved members. This differs from conventional groove welds where S is measured from the joint face. Place S in parentheses to the left of the symbol for PJP welds.
Groove Depth (D)
Per A2.4 §7.2.10.4, groove depth D is the distance from the point of tangency to the top of the member. D does not need to appear on the symbol because the radius of the member inherently determines it. When D is omitted along with S, complete joint penetration is implied.
Which Symbol to Use
The choice between flare-V and flare-bevel depends entirely on the member geometry:
Flare-V Groove (this page)
Two curved surfaces meeting side by side. Both members are round (e.g., two round bars, two tubes). Symbol: Y-shape (two curves). Per A2.4 §7.2.10.2.
Flare-Bevel Groove
One curved surface + one planar surface. One member is round, the other is flat plate. Symbol: reversed-J or C-shape (one curve, one straight). Per A2.4 §7.2.10.1.