metric weld dimensioning 3

[Tmoose]

I believe standard US practice is to dimension a fillet weld by the leg length. I heard from a normally very reliable (but somewhat vintage) source that European standard is to call out the weld throat dimension. I have not been able to confirm (or deny) that after pretty extensive Googling.

Does anyone know the truth, and governing spec?

thanks,

Dan T

 

[CoryPad]

Yes, it is standard to identify the throat dimension. ISO 2553 Welding and allied processes -- Symbolic representation on drawings -- Welded joints is one source.

 

[racookpe1978]

Yes, that is the practice.

Oddly, I have had yet to find a valid (metric units, Euro-fillet throat dimension) fillet weld gage. The standard US fillet gages can be used of course, but the numbers (labels) for each size must be "converted" to a "mm throat length" equivalent.

And, obviously, require the assumption that both legs are the same size, and that the fillet is actually at a 45 degree angle in a 90 degree joint.

 

[tbuelna]

ISO weld standards are used in the US. You can use whichever method (AWS or ISO) of specifying your weld dimensions that suits you. Just be sure to clearly specify on your engineering documents which standard you are using.

 

[kingnero]

I use one of these:

 

[CELinOttawa]

Nice tool kingnero: Who makes it / Where did you buy it?

 

[kingnero]

Commonly available in Western Europe:
Mine is Facom (

http://www.facom.fr

) - item reference: DELA.1960

But as (almost) everything here welding related has only the throat specified (and not the leg length), you can buy those from about every welding wholesaler.

Easy as pie: the two 'legs' make a 90° corner, and you just slide the middle part towards the weld. If the weld is symmetrical, you read the throat from the vernier.
If the weld isn't symmetrical, you still have got to eyeball it...

the angles on each extension are for checking weld preparation (V-grooves).

 

[gtaw]

In many respects, the welding symbols used by ISO 2553 are very similar to AWS A2.4, However, using the ISO system, one can specify either the leg or the theoretical throat dimension of the fillet weld. As is the case with AWS A2.4, the size of the fillet weld is placed to the left of the weld symbol. If the dimension is prefixed by the letter "Z", it is a leg dimension. If the size is prefixed by the letter "a", the dimension is the theoretical throat dimension. The size of the fillet weld is defined by AWS as the largest inscribed isosceles right triangle. The theoretical throat dimension is the shortest distance from the weld root to a line drawn from toe to toe.

Best regards - Al