Edge Weld Symbol
The edge weld symbol calls for a weld along the edges of two or more parallel or nearly parallel members, such as flanged sheet edges. It is drawn as parallel lines closed at the far end, below the reference line for the arrow side or above for the other side, with the weld size on the left and length on the right.
How to read the edge weld symbol
An edge joint puts two sheets face to face (often with their edges flanged up) and welds across the exposed edges. The symbol shows the parallel members, closed by the weld at the end.
Older drawings used separate flange-edge and flange-corner symbols for these joints; current practice uses the edge weld symbol. Side reads as usual: below the line, the arrow side; above, the other side.
What each dimension position means
| Position | Meaning |
|---|---|
| Left (S) | Weld size, the depth of fusion from the edge. |
| Right (L) | Length, or length-pitch for intermittent edge welds. |
| Flange dimensions | Flange height and radius are drawing dimensions, not part of the symbol. |
| Tail | Process and filler, often GTAW with no filler on thin sheet. |
Example callout, read aloud
“Weld the edges of the flanged sheets on the arrow side to a size of 1/16 inch along the full length, using gas tungsten arc welding.”
Example: reading the callout piece by piece
- Edge weld symbol below the line: weld the arrow-side edges.
- 1/16 left: fuse 1/16 inch down from the edge.
- No length: weld the full joint length.
- GTAW in the tail: gas tungsten arc welding.
Result: Weld the edges of the flanged sheets on the arrow side to a size of 1/16 inch along the full length, using gas tungsten arc welding.
When it is used
- Thin sheet enclosures, ducts and containers where flanged edges are fused together.
- Sealing the edges of parallel sheets that are not loaded heavily.
- Joints where a butt or fillet would burn through thin material.
Common mistakes
- Using an edge weld where the joint carries high load. Edge welds are shallow; use a groove or fillet where strength matters.
- Looking for flange height on the symbol. Flange dimensions belong on the drawing view.
- Using an old flange symbol on a new drawing. Use the edge weld symbol and cite the current AWS A2.4 edition.
- Confusing it with a square groove. A square groove is a butt between edges in line; an edge weld joins parallel members along their edges.
Related weld symbols
- Square groove weld: A square groove joins edges butted in line.
- Seam weld: Seam welds seal lapped sheet.
- Spot weld: Spot welds join lapped sheet at points.
- Fillet weld: Fillets join sheets at an angle.
- Surfacing weld: Surfacing deposits on a surface, not an edge.
Every weld symbol page: welding symbols chart
Calculators and further reading
Frequently asked questions
What is an edge weld?
A weld along the edges of two or more parallel or nearly parallel members, such as flanged sheet edges.
Did the edge weld replace the flange weld symbols?
Current practice uses the edge weld symbol for these joints; separate flange-edge and flange-corner symbols appear on older drawings.
Where does the size go on an edge weld symbol?
To the left of the symbol, as with most weld symbols.
Can edge welds be intermittent?
Yes. Length and pitch go to the right of the symbol, as for fillets.
Sources
- AWS A2.4 Standard Symbols for Welding, Brazing, and Nondestructive Examination, American Welding Society
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