§6.13 · Figure 7.15Symboles de contour et de finition
Les symboles de contour précisent la forme exigée de la surface de la soudure : plane, convexe ou Concave. Sept lettres de désignation de finition (G/M/C/H/P/R/U) indiquent la méthode mécanique lorsqu'elle est exigée. Selon A2.4 Clause 6.13, les désignations précisent uniquement la méthode. La D1.1 Table 8.1 régit les critères d'acceptation du profil de soudure pour l'acier de construction.
7 lettres de désignation de finition
Lorsqu'une méthode mécanique de finition est exigée après soudage, la lettre de désignation est placée à côté du symbole de contour. Selon §6.13.2, ces désignations précisent uniquement la méthode — ni la qualité ni la rugosité de la surface.
| Letter | Finishing Method | Common Use |
|---|---|---|
| G | Grinding | Most common — CJP groove welds at moment connections, fatigue-critical joints |
| M | Machining | Precision surfaces — bearing seats, rotating equipment |
| C | Chipping | Removing slag or excess Métal Fondu with pneumatic chisel |
| H | Hammering | Peening operations — Relaxation des Contraintes in specific applications |
| P | Planishing | Smoothing with a flat-faced tool — sheet metal applications |
| R | Rolling | Rolling to smooth or cold-work the surface |
| U | Unspecified | Mechanical finishing required, method at Fabricant’s discretion (§6.13.3) |
Figure 7.15Applications de contour sur soudures sur chanfrein
A2.4 Figure 7.15 montre trois applications pratiques des symboles de contour et de finition sur des soudures sur chanfrein :
Figure 7.15 — Flush and Convex ContourConseil pour l'examen CWI : Le symbole de contour se place au-dessus du symbole de soudure, pas à côté. Sans lettre de finition, le contour peut être obtenu par la seule technique de soudage. La lettre G (meulage) est la désignation de finition la plus souvent examinée au CWI.
Questions sur le symbole de contour
Section 6.13, there are three contour shapes: flush (flat, indicated by a straight line), convex (raised, indicated by a convex arc), and concave (recessed, indicated by a concave arc). The contour symbol is placed on top of the weld symbol on the reference line. When a contour symbol appears without a finishing designator letter, the contour may be achieved by any method including welding technique alone. When a finishing designator letter is added (G, M, C, H, P, R, or U), a specific mechanical finishing method is required after welding.Section 6.13.2. When you see G next to a contour symbol (flush, convex, or concave), it means the weld must be mechanically ground to achieve that contour. For example, a flush contour symbol with G means grind the weld flush with the base metal surface. The finishing designator specifies the method but does not specify the quality or roughness of the finish. Grinding is the most commonly specified finishing method in structural steel fabrication, particularly for CJP groove welds at moment connections where flush surfaces are required for fatigue performance.Section 6.13.2 and Section 6.13.3 define 7 finishing designator letters: G for grinding, M for machining, C for chipping, H for hammering, P for planishing, R for rolling, and U for unspecified mechanical finishing method. Each letter is placed next to the contour symbol to specify how the weld surface must be finished. The letters do not specify the quality or surface roughness of the finish. U is used when mechanical finishing is required but the specific method is left to the fabricator. These designators apply only to mechanical finishing methods, not to contour achieved by welding technique alone.Section 6.13. Flush contour is required for fatigue-critical connections because weld reinforcement creates stress concentrations at the weld toes. D1.1:2025 Clause 7.23 specifies flush finishing requirements for butt joints in cyclically loaded structures. Convex contour is acceptable for most statically loaded connections where fatigue is not a design consideration.