European Weld Symbols — EN 22553 Standard Welding Symbols Guide
Complete reference for weld symbols per EN 22553 (equivalent to ISO 2553). Standardized symbols for European structural steel fabrication: fillet welds, butt welds, plug welds, groove welds, and seam welds. Symbol placement (arrow side, other side, both sides), supplementary symbols, and example callouts.
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Basic Weld Symbols — EN 22553
| Weld Type | Symbol | Illustration | Description |
|---|---|---|---|
| Fillet weld | △ | Triangular cross-section | Most common structural weld |
| Butt weld (square) | ‖ | Square edges | Thin material, full penetration |
| Single V butt | V | V-shaped groove | Single-sided full penetration |
| Double V butt | X | Double V groove | Double-sided full penetration |
| Single bevel | ╱ | Bevel on one plate | Single-sided, one plate beveled |
| Double bevel | K | K-shaped groove | Double-sided bevel |
| Plug weld | ○ | Circular hole filled | Lap joints, light framing |
| Spot weld | ● | Circular spot | Thin sheet metal |
| Seam weld | — | Continuous seam | Thin sheet, continuous |
Symbol Placement
EN 22553 uses a reference line with an arrow:
Other side symbol
┌──────┐
│ │
────────┤ ├──── arrow
│ │
└──────┘
Arrow side symbol
- Arrow side — Weld on the same side as the arrow points to
- Other side — Weld on the opposite side from the arrow
- Both sides — Symbols on both sides of the reference line
Fillet Weld Callout Structure
Standard Callout Format
α l_1 (e)
───◇───────────────
a l_2 n ×
| Component | Meaning | Example |
|---|---|---|
| a | Throat thickness (mm) | a4 |
| α | Included angle (degrees) | — |
| l_1 | Weld length (mm) | 100 |
| l_2 | Intermittent weld length (mm) | 50 |
| n × | Number of intermittent segments | 4× |
| e | Spacing between segments (mm) | (200) |
Example Callouts
| Symbol Callout | Meaning |
|---|---|
| ◇ a4 | 4 mm throat continuous fillet weld |
| ◇ a6 100 | 6 mm throat, 100 mm long fillet weld |
| ◇ a5 6×50(200) | 6 intermittent 50 mm welds of a5 at 200 mm centres |
| ◇ a8 around | 8 mm throat continuous fillet all around |
| △ | Arrow side fillet weld only |
Butt Weld Symbols
Single-Sided Butt Welds
| Symbol | Full Penetration Notation | Example Callout |
|---|---|---|
| V | U symbol inside V | V ✓ indicates full pen |
| V | No symbol | Partial penetration |
Double-Sided Butt Welds
| Symbol | Meaning | Typical Root Gap |
|---|---|---|
| X | Double V butt — both sides | 2-3 mm |
| K | Double bevel — one piece square | 2-3 mm |
Supplementary Symbols
| Symbol | Meaning | Placement |
|---|---|---|
| ◇ (flag) | Field weld | At the arrow-reference line junction |
| ○ (circle) | Weld all around | At the arrow-reference line junction |
| ⌴ (square) | Backing strip | Below reference line |
| ✓ | Full penetration | Inside the V-symbol |
| ∪ | Flat finish | Above the weld symbol |
| ⌢ | Convex finish | Above the weld symbol |
| ⌣ | Concave finish | Above the weld symbol |
Field Weld Symbol
The flag symbol at the arrow-reference line junction indicates that welding is to be performed in the field (site welding) rather than in the fabrication shop.
All Around Symbol
The circle at the arrow-reference line junction indicates that the weld extends continuously around the joint perimeter.
Practical Examples
| Detail | Symbol Callout |
|---|---|
| 6 mm fillet both sides, full length | ◇ a6 (both sides) |
| 8 mm fillet, all around | ◇ a8 with ○ at junction |
| Field weld, 5 mm fillet, 100 mm long | ◇ a5 100 with flag |
| Full penetration V-butt | V with ✓, a=t |
| Intermittent fillet, 4 runs of 50 mm at 200 mm centres | ◇ a4 4×50(200) |
Frequently Asked Questions
What is the difference between EN 22553 and AWS A2.4 weld symbols?
EN 22553 (ISO 2553) uses a dashed reference line where symbols above and below distinguish arrow side from other side. AWS A2.4 uses the same line but symbol placement differs slightly. The most significant difference is in the weld all around symbol (○ in both) and field weld flag (◇ in EN 22553, flag in AWS). EN 22553 uses throat thickness "a" while AWS typically uses leg length "w".
How do I indicate a field weld on EN 22553 drawings?
A field weld is indicated by a flag symbol at the junction of the arrow and reference line. The flag points toward the arrow tail. Without the flag, the weld is assumed to be performed in the fabrication shop. Site welding requires additional quality control per EN 1090-2.
Related Pages
- Weld Capacity — Fillet weld per EN 1993-1-8 Clause 4
- Weld Inspection — EN 1090-2 inspection methods
- Welding Procedure — EN 1090-2 WPS requirements
- All European References
Educational reference only. Weld symbols per EN 22553:2019 (ISO 2553:2019). Verify symbol meaning per project welding specification. Results are PRELIMINARY — NOT FOR CONSTRUCTION without independent verification.
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