Parts of a welding symbol
Every welding symbol is built on the same frame: a reference line, an arrow that points at the joint and an optional tail. Where the weld symbol sits on that frame says which side of the joint gets the weld.
Parts of a welding symbol: AWS and ISO
This is where AWS and ISO really differ. In AWS A2.4 a symbol below the line means the arrow side and above means the other side. In ISO 2553 system A the solid line is the arrow side and the dashed identification line is the other side, wherever the dashed line is drawn. ISO 2553 system B drops the dashed line and follows the AWS rule.
See how to read welding symbols for the dimensions, the tail and a worked example.
Frequently asked questions
Which parts of a welding symbol appear on a welding drawing?
This legend covers reference line and arrow, other side weld, tail. Project legends may add more.
Are these symbols different in ISO and AWS?
3 of the 3 are drawn differently. Each symbol page shows both forms side by side.
Can I download these symbols?
Yes. Each symbol page has free SVG files, and the hub has printable PDF charts.
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