Bevel لحام الأخدود Symbol
How to read a bevel groove رمز اللحام — the broken arrow convention, perpendicular leg rule, groove angle, and D1.1:2025 prequalified CJP joint details.
Which Member Gets the Bevel?
The broken arrow is the most important — and most commonly misunderstood — convention in اللحام symbol reading. Per A2.4 §6.4.1:
Broken arrow (kinked) — the arrow has a visible bend or kink in its shaft. It points at the member that must receive the edge preparation. The fabricator has no choice — that specific member gets beveled.
Straight arrow — per A2.4 §7.1.3.2, a straight arrow means either member may have the desired edge shape. The fabricator can choose which member to bevel based on access, material السماكة, or shop preference.
The broken arrow applies to all asymmetric groove types: bevel groove, J-groove, and flare-bevel groove. It does NOT apply to symmetric أنواع like V-groove, U-groove, or flare-V groove.
Prequalified Single-Bevel CJP Details
| Process | Designation | Root Opening | Groove Angle | Positions |
|---|---|---|---|---|
| SMAW | B-U4a | 1/4" | 45° | All |
| SMAW | B-U4a | 3/8" | 30° | All |
| GMAW/FCAW | B-U4a-GF | 3/16" | 30° | All |
| SAW | B-U4a-S | 1/4" | 45° | F only |
| SAW (backgouge) | B-U4b-S | 0 | 60° | F only |