Weld all around and field welds
Look where the arrow meets the reference line. A circle, a flag, both, or neither: each one changes the job.
What do the marks where the arrow meets the reference line tell you?
Two marks at the junction
- Open circle: weld all around. Keep going around the whole joint, with the same weld the whole way.
- Flag: field weld. Made on site, not in the shop. This matters for planning, access and inspection.
- Neither: a shop weld, made only where the symbol shows.
AWS A2.4 and ISO 2553 use the same circle and flag.
Questions
- What does the circle on a welding symbol mean?
- An open circle where the arrow meets the reference line means weld all around: the weld continues around the whole joint, for example all the way around a tube welded to a plate.
- What does the flag on a welding symbol mean?
- A flag where the arrow meets the reference line means field weld: the weld is made on site during erection, not in the shop. No flag means a shop weld.
- Does it matter which way the flag points?
- Not for its meaning. Guides differ on which way it should be drawn, so read the flag itself, not its direction.
- What did a black dot mean on older drawings?
- On older drawings a filled black circle at the junction was used for a field weld. Current drawings use the flag.
Explained in our own words. For the full rules, see AWS A2.4:2020 and ISO 2553:2019.