Flare Groove Weld Size with Symbol

[Boiler106]

Using AISC...

The weld size, E, of a flare groove weld is 5/16R = 5/16 x 2t for HSS = 5/8t per Table J2.2.

Is it necessary or even customary to provide the size E in parenthesis in the weld symbol if its dictated by Table J2.2?

I often see engineers specifying the size as if it were a fillet weld, i.e. 1/4.

If anyone has a source, please direct me.

 

[JAE]

We always use (E) on the weld symbol showing the effective throat. Never without parentheses.

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[Lomarandil]

Agreed, I find it better practice to specify the (E) and let the welder work out his process to get there.

----
The name is a long story -- just call me Lo.

 

[sandman21]

We do not give a size as a prequalified weld only has an E with no S to specify. A weld which does not achieve the E listed would not be a prequalified weld

 

[dik]

Good point JAE... have done that for decades.

Dik

 

[Boiler106]

i guess my question is, if there is only one weld size possible for a given bar/HSS radius, why would it be necessary to provide the size?

Or perhaps, is there more than weld size possible (without fillet weld reinf)?

 

[CANPRO]

Boiler106 - the radius on the HSS isn't always what you expect it to be...if you give them the required effective throat then they can adjust accordingly. I take two paths with this - if by the numbers I need an insignificant amount of weld or its not structural, then I'll just keep it simple and show the flare bevel symbol. If it is critical that I get a minimum effective throat out of the weld, then I'll specify the minimum that I need.

 

[JAE]

...if there is only one weld size possible for a given bar/HSS radius...

If you look at Table 8-2 for a Prequalified weld for a Flare-Beel Groove Weld there are different "Total Weld Sizes (E)" listed depending on the welding process.

If you, the designer, are dependent on a particular throat size for a particular load, you'd want to specify the throat that is assumed/required.


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[UcfSE]

only one weld size possible for a given bar/HSS radius

For large radii, a full fill is not always required and may not be practical. A few times I have calculated throat on a partial fill and indicated this in the drawing. That's not prequalified of course.

 

[SocklessJ]

Look at the Notes in Table 8-2 of the manual (I'm looking at the 13th ed.). Note 12 states:

"The effective throat thickness (E) is based on joints welded flush)"

So basically, if you fill the joint flush, the weld is pre-qualified, and you can take credit for the effective throat in the table. This is what you'll commonly see for square/rectangular HSS, and rarely do I see an effective throat in the weld symbol.

However this isn't appropriate for circular sections like pipes (such as the weld of a guardrail post to an angle), where filling flush is overkill. In that case you'll want to specify the effective throat required by your calculations. It' then up to the fabricator to figure out how deep to fill the joint. This weld will not be pre-qualified, and the fabricator will need to prove (via macroetch) that a given fill depth (and other variables) achieves the effective throat you asked for.