D1.1 min max fillet weld size

Date 07-01-2004 01:24

Ted,

I don't have my code book at home, only my trusty pocket handbook, but you need to check out "underrun". It allows for a maximum of 10% of the length of a continuous fillet weld to underrun the specified size by 1/16" (.062")without correction. There are additional limitations that apply to web-to-flange welds.

Adder: 1. The weld size need not exceed the thickness of the thinner part joined. 2. Cyclically loaded structures have a 3/16" minimum size.

By jwright650 (*****)

Date 07-01-2004 11:35

Ted,
Another thought on this, other than what thirdeye had already mentioned is this....

D1.1 :2004 paragraph 5.13 Conformance with Design says..." The sizes and lengths of welds shall be no less than those specified by design requirements and detail drawings, except as allowed in Table 6.1. The location of the welds shall not be changed without the approval of the engineer.
Table 6.1 Visual Inspection Acceptance Criteria Item(6) undersized welds
catagories for Statically Loaded Nontubular, Cyclically Loaded Nontubular, & Tubular (all loads), "the size of a fillet weld in any continuous weld maybe less than the specified nominal size (L) without correction by the following amounts (U):
Specified (L) is less than or equal to 3/16 = allowable decrease (U) is less than or equal to 1/16. [Note: Other sizes of fillets/allowables are listed but I didn't include them]
In all cases, the undersized portion of the weld shall not exceed 10% of the weld length...."

As for the maximum size allowed... hmmm, The code specifes max sizes for lap joints(paragraph 2.3.2.9), but if the extra size doesn't interfere with the usefullness of the part, I'm not sure there is anything other than heat input to limit the max size allowed, unless I'm missing something somewhere.
Hope this helps,
John Wright

By tab_1999 (**)

Date 12-06-2007 20:05

John,
This post may be dead but I'm gonna give it a try.

I would like to add to the Max. question by saying unequal-leg fillet welds are not addressed specifically/directly.
In relation to the max size Fillet weld. Off-leg Fillet Welds seem to be common on FCAW. AWS references a Table of Acceptable/Unacceptable Weld Profiles that also addresses excessive Convexity @ .07 + .06, in the footnote I believe.

Its my opinion that the above formula, discounts oversized/offleg welds if the formula and notes are followed.
e.g. using the perfect Fillet or equal leg and the criteria stated, how could one accept the excess weld? ( without an Engineering, accept as-is to an RFI or NCR)

There is also a section that specifically states that excess weld metal shall be removed. ( I would have to look the section up). I have the AWS D1.1 2004 edition

Any thoughts?

By jwright650 (*****)

Date 12-06-2007 21:56

D1.1:2006, Paragraph 5.26.1.1 The "excessive material shall be removed" is referring to Overlap, Excessive Convexity, and Excessive Reinforcement, which all are addressed in Figure 5.4.....I don't think that would apply to an unequal legged fillet though.

Also see Annex A

By aevald

Date 12-06-2007 23:24

Hi John, this might be a bit off topic, but isn't the basis for considering a weld size to meet the correct through section requirement to ensure sufficient weld strength? Please indulge me a bit here. If you have an unequal leg fillet, yet the short leg of this fillet is of sufficient size when considering the through section size and the long leg of the fillet amounts to additional filler and not a lack of it. Isn't this more a case of additional time and material being used than would be required or is this a case of considering distribution of stresses as unequal within the weld metal due to the shape and position of it? Is there any possibility of an adverse effect due to heat-input with regard to alloy type or something else along these lines? This thread has raised some questions for me and that's why I'm asking. Many thanks for consideration and regards, Allan

By jwright650 (*****)

Date 12-07-2007 11:39 Edited 12-07-2007 12:36

Hi Allen,
No I don't think you hve taken this off-topic...you have good questions.

I was only trying to look at this from an inspection point of view and trying to determine if an unequal leg fillet is acceptable or rejectable according to what we have been given in D1.1.

I agree that to achieve a fillet weld that meets the min leg and also meets the throat requirements but is unequal will no doubt waste both time and materials vs placing a correctly dimensioned fillet...but is the unequal leg fillet rejectable?

I still feel that if the weld meets the min leg and throat requirements, you would have to accept it (up to a point)....I could see that a multipass fillet could take on some really weird shapes and make you stand back and really look hard at the situation...I also think someone could take my senario to an extreme. Maybe the code writers could develope a ratio between the leg sizes to keep this somewhat in check so that an inspector would have more to go on....

Now as for the unequal distribution of stresses causing a concern, or adverse effect of heat input...you have asked the wrong person...LOL, hopefully someone will chime in and help me out with those questions.

edit: I have attached a sketch(you should rotate it CCW 90* for best viewing)...just for conversational purposes, it would be a very extreme condition, and most likely a multipass weld to achieve the weld shown on the left....but again, it is just for conversation....

Attachment: Sketch1.pdf (5k)

By aevald

Date 12-07-2007 17:28

Hello John, I believe my take here is that unless there are other issues, ie., roll-over(exhibiting lack of fusion), undercut, or other rejectable issues that would require correction, for any weld, then short of engineering issues relative to undo stresses, or other mechanical issues, the excess filler metal is more of a production cost and material cost issue and I really can't see the need for removal of excess filler metal. Unless I'm missing something I believe this is somewhat what you are saying?
I know that many times when angle type connection clips are welded to the ends of certain size beams, it is next to impossible to end up with equal leg fillets due to the cramped quarters and lack of gun angle access. I would assume that these types of issues are taken into consideration. Regards, Allan

By ctacker (****)

Date 12-08-2007 01:43

where I inspect, our company's website says we have some of the best welders in the industry, and i have the authority to reject any weld for any reason. I allow a 1/4 oversize weld on >3/4 welds and no undersize, that gives a 1/4 difference in leg lengths and <1/2 is 1/8 and betwwen 1/2 to 3/4 i allow 3/16 oversize! its getting harder and harder to find decent welders that can stay within that!

By tab_1999 (**)

Date 12-07-2007 18:32

Thanks,

I guess its just one of those things that make me question why so much is spent in weld design calcs. etc. when the sizes are pretty much ignored.
It's my experience that these types of welds ( I mean substantially off-leg, using.045 Flux Core, running HOT for small Fillet Welds 1/4 to 5/16 ) generally have more issues than not. Some examples are cold roll, lack of fusion, undercut, multi-pass to cover UC etc..
I guess I'll chalk it up as it always catches my attention and causes me to just inspect a little closer. It also helps me realize one of the reasons the cost of work creeps up.

Thanks for staying up on these old posts.

All of ya!

There is no shortcut to anyplace WORTH going!!....

By CHGuilford (****)

Date 07-01-2004 13:27

Interesting problem and I'm not sure how clarify it. Thirdeye and John have given the portions of D1.1 that addresses fillet size.
I believe it all comes down to the actual wording of the notes and contract specs. Invoking D1.1 as the welding code means that certain criteria must be met, as you know, but does not mean the customer cannot require more stringent tolerances. If that was requested after the bid, then the criteria would have to be per mutual agreement and naturally the cost would be negotiated.
Practically speaking, +/- 0.06" (nearly 1/16") shouldn't be too difficult with many welding processes.
It might help your case if you point out that the tolerance would allow the entire weld to be slightly under 1/16" (0.06") not just 10% of the weld length, and that might not be what the customer really wants. That may help them to decide that D1.1 criteria is suitable for the project without the 0.06 tolerance.
It sounds like you are dealing with the nuclear industry. If so, I wish you luck, but it might be easier to live with it.

Chet Guilford

By jwright650 (*****)

Date 07-01-2004 14:19

Ted,
I meant to mention and failed to... the Commentary section of D1.1, particularly C5.13, and C5.14.
John Wright

By thirdeye (***)

Date 07-01-2004 14:23

Ted....Chet has a point regarding the wording of the notes. Notes can be general, localized (appply to certain areas of the dwg.) or specific (in which case a particular specification applies). A specification, being a more detailed description, would most likely take precedence over a general note. It should be determied if the specific reference to a supporting document like AWS D1.1 takes precedence over the general tolerance notes.

By swnorris (****)

Date 07-01-2004 17:02

Hi All,

I'm not aware of anything in D1.1 that specifies any maximum fillet size limitations, with the exceptions in C5.13 and the other regarding lap joints that John has already mentioned. I'll just add that the the concept of the limitations on the maximum size of fillet welds in lap joints along the edges of the material is based on an inspector being able to identify the edge of the plate to properly position a weld gage. This allows the inspector a basis to properly distinguish the actual weld throat for plates 1/4" or larger in thickness.

Here's a link to an interesting article from a 1993 printing of Steel Inspection News about alternate acceptance criteria for weld sizes:

http://www.steelstructures.com/StlInspNews/NEWS%20weld%20size.htm

By TRC

Date 07-01-2004 20:01

thirdeye, John, Chet and Mr. Norris I can't thank you all enough for taking your valuable time and responding to my post. This is what I was looking for and hopefully I can get them to understand with the information supplied. Respectively- Ted