Basic Welding Symbols Guide (AWS)
A quick reference for deciphering American Welding Society (AWS) symbols found on engineering drawings and blueprints.
| Weld Type | Symbol Geometry | Meaning & Application |
|---|---|---|
| Fillet Weld | Right Triangle (△) | Used for tee, lap, and corner joints. The vertical leg of the triangle always faces the left. |
| Square Groove | Parallel Lines (||) | Butt joint with no beveling required. Used on thinner materials. |
| V-Groove | V | Both members are beveled to form a V shape. Requires deeper penetration. |
| Bevel Groove | Right Half-V (\|) | Only one of the two members is beveled. |
| Plug / Slot Weld | Rectangle | Used to join overlapping members by welding through a hole in one member. |
| Weld All-Around | Circle at the Junction | Indicates the weld should continue completely around the joint. |
| Field Weld | Flag at the Junction | Indicates the weld must be performed on-site (in the field), not in the shop. |
Arrow Side vs. Other Side
The reference line is the horizontal line the arrow attaches to.
- If the weld symbol hangs below the reference line, the weld is applied to the arrow side (the side the arrow points to).
- If the weld symbol sits above the reference line, the weld is applied to the other side (the opposite side of the joint).
- If symbols are on both sides of the line, the joint is welded on both sides.