AWS 2.4.2.3 is not clear as to what definition of “size” of a fillet weld is being considered…
Here’s the words in Clause 2.4.2.3 Minimum Length which states: “The minimum length of a fillet weld shall be at least four times the nominal size, or the effective size of the weld shall be considered not to exceed 25% of its effective length.
To me, this is clear as mud! And, worse, it has two parts… (1) four times nominal size of what? The thickness of the base metal? And, (2) not to exceed 25% of the effective length of what? The whole length of the joint? Two different things here, right? One is thickness, and the other is length.
I’m confused because I’m not sure if this clause refers to (1) a cross sectional “leg size,” where, I quote AWS Welding Inspection Technology, “To determine the size of a fillet weld, you must first know whether the final weld configuration is convex or concave…
Furthermore, “”a fillet weld size for equal leg fillet welds is described as the “the leg length of the largest isosceles (two legs of equal length) right triangle which can be inscribed within the fillet weld cross section.””
OR, does this clause refer to the (2) Longitudinal Length of the fillet weld? If so, then I could assume that if we’re still talking about thickness of base metal, what would happen if I had two pieces of 1” thick plate 10 foot long configured in a T joint, then the fillet weld size would need to be a minimum length of 4 inches long. Is that what this means?
Furthermore, what would happen if the length of my T joint was 10 foot long? Would the minimum size of any fillet weld be only 4 inches along the whole length of the 10 foot long part?
And then (2), if the effective size (longitudinally speaking) is not to exceed 25% of the effective length, then my 10 foot T joint could have a maximum of 4 ft of weld.
There seems to be a lot going on with this clause, and silly me for overthinking this subject, but again, I’m not sure how to interpret this. And, what’s worse, is that there’s more unclear words in the remaining sections of 2.4. Effective Areas.
Any good sources out there to clear this up?
Thanks
Jim,
It is very poorly worded.
I do not work in imperial so sorry, have to be in metric.
AWS deals with throat thickness, not leg length so this is my interpretation.
"The minimum length of a fillet weld shall be at least four times the nominal size, or the effective size of the weld shall be considered not to exceed 25% of its effective length."
If the nominal size of a fillet weld is 10 mm then the minimum length of the fillet weld is 40 mm.
If the effective length of the fillet weld is 40 mm then the effective size of the fillet weld should not exceed 10 mm.
I cannot understand why nominal size and effective size are used in the same sentence when there is nothing in AWS D1.1 or 3.0 that explain the difference in terms.
Where are you Al when we need you ?
Jim,
"To me, this is clear as mud! And, worse, it has two parts…
"(1) four times nominal size of what?"
Four times the size of the fillet weld.
"(2) not to exceed 25% of the effective length of what? The whole length of the joint? Two different things here, right? One is thickness, and the other is length."
The effective length of the weld.
If the fillet weld is across the whole length of the joint" that is the effective length of the weld. Or if the weld is say, 2" @ 12", the effective length of the weld is 2".
In either case, the effective length excludes any existing crater at the end of the weld...
Effective length of weld is defined as "The length throughout which the correctly proportioned cross section of the weld exists. In a curved weld, it shall be measured along the weld axis."
I can rest, you folks did a fine job of explaining.
Part of the CWI examination is to see if the reader can understand what is written. Not poking a stick that this poster, but it is amazing how many people can't understand a sentence if there is a comma in it.
With regards to size, the AWS welding symbol specifies the weld size by the leg of the inscribed isosceles right triangle. Commercially available fillet gages provide two templates, one for the convex and flat fillet face and a template for concave fillet welds. In the case of the concave template, it indicates the leg size of the inscribed isosceles right triangle, not the throat dimension.
Just like the code isn’t going to provide instruction on how to weld with SMAW, the code isn’t going to provide instruction on how to measure a fillet weld. The user is expected to have a fundamental understanding of the technology. That comment doesn’t apply just to AWS codes, but all codes in general.
Al
C'mon Al,
Help us out here.
I am struggling with the wording in the code and after re-reading my post I am struggling with that as well.
First part - no problem.
Second part - why maximum and not minimum ?
If I have a 40 mm long fillet and I put an 11 mm or 12 mm fillet why is that not code compliant ?
It is a waste of time and money putting fillets larger than required but why would code compliancy be dependant on that ?
Cheers,
Shane
Now you're asking me to provide the logic behind the provisions of the Farm Code? That's like trying to justify some of the provisions of ASME! They are the words handed down to us mere mortals from a lesser god. Our's is not to reason why.
To my way of reasoning, the word minimum is used because the length can't be shorter than ---- to ensure sufficient heat is generated to ensure "slow cooling". Don't forget to consider the “smallest” size fillet weld has to be used regardless of the load being transmitted to ensure slow cooling as well. That's why you do not see anything written in the Farm Code regarding "seal welds." Both provisions, i.e., minimum fillet length and minimum size based on material thickness, are included to ensure sufficient heat input is generated to avoid a martensitic microstructure is not developed in the HAZ provided sufficient preheat is used.
Bottom line: three conditions have to be satisfied:
1) Sufficient preheat based on chemistry and thickness of the base metals,
2) Minimum size based on base metal thickness, and
3) Minimum weld length.
The three conditions are a conservative means of ensuring martensite isn’t developed in the HAZ.
I could be wrong, it happens several time every day. My wife used to keep close track of my errors. She keep a record of them in several large three ring binders. Every time I showed signs of being over confident, she would put out one of the binders and point out one of my recorded blunders. I never point out the blunders she missed.
Al
Thank you my friend for the response.
You have not answered my question regarding why maximum is noted and not minimum ?
As for ASME - I have just had to complete a 30 minute survey as to why I love being an ASME volunteer !
Obviously not for the free drinks !
The maximum length is a different paragraph. I'm not sure which paragraph you are referring to.
Al
Is this not stating maximum size Al or am I misinterpreting ?
or the effective size of the weld shall be considered not to exceed 25% of its effective length."
All it is saying is that you can't have fillet weld that is specified as 1-inch leg x 1/4-inch long.
Don't forget, you are looking at the design parameters, not the inspection criteria.
Al
Hi Al
Here is something for you and others related to seal welding since you mentioned it.
D1.1 2015 does indeed have new language regarding seal welding. Specifically it provides data related to wrapping welds on the opposite side of a common plane and inspection of CJP joints with seal welded backing and UT. The UT guidance is in the commentary. The wrapping on opposite sides of a common plane data is found in Clause 2.9.3.5
Here also is a great link to some commentary on seal welding by Duane Miller. This gives some good information related to hot dip galvanizing and considering load path changes that may occur as a result of seal welding.
http://www.jflf.org/v/vspfiles/assets/pdf/design_file6.pdfSome recent projects have compelled me to spend a lot of time with AGA (American Galvanizing Association) documents related to seal welding.... Our weld manual is now much improved.
I wasn't thinking along the line of wrapping the weld around the corner where the welds are on opposite planes, but you're right to point it out.
I was thinking of the skinny little welds that are not intended to transmit loads (but they do), with the intension of "sealing" out the weather.
Spending the day qualifying welders for fillet welds. Still trying to kiss the root to get the required fusion and yet obtain the proper size fillet. Same old problem of not getting fusion in the root due to the welders technique of using the circular motion to get the right size weld in a single pass. They consistently get a perfect slag line down the entire root. The FCAW and GMAW never fail to provide me an opportunity to burn some wire. Frustrates the hell out of them youngsters when the “old fart” can show them how it done on the first try.
Al
