1 - Weld all around
The first symbol (open circle) is used when we want to indicate welding around the entire contour, see example below.
2 - Field weld
A detail for the flag symbol is that its presence indicates that the welding must be done “in the field” or at the installation of the equipment.
The absence of this flag indicates that welding must be carried out at the factory.
3 - Melt through
The symbol is applicable to a weld made on one side only and indicates full penetration.
When root reinforcement is critical, this should be indicated on the left side of the symbol, please look at the example given below.
4 - Consumable insert
This symbol must be accompanied with details about the type of consumable, with a note on the drawing or even using the tail space.
5.1 - "Backing"
When backing is required to achieve full penetration, the rectangle symbol is used.
If the backing is required to be removed after welding, an “R” must be inserted inside this rectangle.
Note that the backing symbol and the plug weld symbol are the same. But the context will make it clear what are symbol's intention.
5.2 - Spacer
The spacer name and picture are usually self-explanatory (see it below).
In the example below, a 12 X 6 mm spacer made of low carbon steel type (SAE 1020) is used:
Contour (6, 7 and 8)
A flush symbol means that the weld reinforcement must be removed.
The weld should be flush or level with the base metal.
This is a recognized and established method to increase fatigue resistance, but it is also used to facilitate access to non-destructive tests such as ultrasound examination.
It is understood that this AWS symbol (contour) refers to the condition “as welded”, ie without any further mechanical treatment.
I have never seen this symbol used. And besides not seeing any sense in it, I believe that this practice is detrimental to quality.
For example, when convexity symbol is required, a welder may be encouraged to fill more to make the weld more convex.
Examples of the use of other profile symbols:
Finish symbols
There are also finishing symbols, which indicate the method of finishing the weld surface. These symbols are:
- C - Chipping
- G - Grinding
- M - Machining
- R - Rolling
- H - Hammering
- U - Unspecified
Acronyms/letters refer to the first letter of English terms.
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Citation
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