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Up Topic American Welding Society Services / Technical Standards & Publications / Unequal leg lengths per D1.1
- - By Kix (****) Date 11-12-2007 16:49
Does it state anwhere in D1.1 2006 about how much of a difference you can have in your leg lengths of a fillet weld (Vetical leg vs horizantal leg)?. I'm looking for it right now, but i'm haveing probs locating it if it does say anything.

Thanks, Ray C.
Parent - - By jwright650 (*****) Date 11-12-2007 19:38
Ray,
I might be wrong(yeah, it's happened), but I don't remember D1.1 stipulating anything regarding the unequal legs...because you still need to meet the throat dimn and the min leg dimn shown on your drawing anyway...so it probably doesn't matter if the other leg is a bit longer, that extra weld material isn't used in the design calculations anyway.
Parent - - By Kix (****) Date 11-13-2007 17:02
Ok good, because that new code i'm working with ( A TACOM cage code) does stipulate this, but the particular part i'm looking at is to be inspected to D1.1.  The welds are allready undersized, but you know how that goes over with some people " man thats never gona come apart and you don't know what your talking about" lol  I was just looking for something else to back me up so it makes my case look better.  It's in the companies hands now because the customer rquested that i inspect it and i did.  I told that i would never put my stamp on this and the third party inspection that did needs to be talked to.  Undersized weld were not the only problem in case some are wondering.;-)

Thanks, Ray C.
Parent - - By tab_1999 (**) Date 12-04-2007 18:11
Food for thought.

I believe that if you look at the accepted weld profiles noted in AWS D1.1 A5.24, you would have a hard time complying using off-leg fillet welds..

Using Figure 5.4 in the 2004 edition, some changes were made to assist in eliminating/preventing wormy welds and out of proportion welds.

If you look a the desireable welds and acceptable weld profiles and then look at note 1. (limits on convexity)
or You could also assume that all the "extra" convexity outside the equilateral triangle would either be removed (as excessive reinforcement) to the required size  or ( not knowing the specified weld size ) use the longest leg as the starting point for the weld size and  automatically be an undersized weld .

Penny for your thoughts...

p.s. I was using the 2004 Edition
Parent - - By 803056 (*****) Date 12-07-2007 04:12
There are three criteria that must be met when checking a fillet weld. The smallest leg dimension must be at least equal to the specified weld size, the throat dimension must be verified, and the length of the weld must be at least that specified. Provided those criteria are met and none of the unacceptable profiles such as overlap, undercut, excessive convexity, etc. are encountered, it is a good fillet weld.

Reading and using a code is unlike a high school English literature class where what is written is subject to interpretation by every one that reads it. I swear my English literature teacher was high on drugs because I could never see how she came up with her interpretations. I still suspect she and I were reading two different books.

There are terms and definitions that apply to every code. It isn't left to the reader to come up with their own definitions. That being said, the definition of convexity is included in AWS A3.0; paraphrased it is the dimension measured normal to a line connecting the toes of the fillet weld and the face of the fillet weld. The current allowable for convexity are pretty liberal compared to a decade ago.

Based on the constraints listed above and in D1.1 there is nothing wrong with an unequal legged fillet weld.

When I look at a weld, I look for any discrepancy that would result in a weld that is weaker than that specified by the designer. Perfection is a goal every welder should strive for, but the code isn't always looking for perfection. Sometimes "good enough" is good enough. A weld that is larger than required is not prohibited provided it doesn't interfere with a mating component.

Best regards - Al
Parent - - By ctacker (****) Date 12-07-2007 06:02
Lemme ask you Al, how do you check the hight of a convex weld when can only look at it from above (not getting eye level and looking down the cross section of a weld)
some type of contour gauge would be nice to push into the corner then measure the gap on the gauge!
Parent - - By aevald (*****) Date 12-07-2007 07:36
Hello ctacker, I believe GAL has just such a gauge, as I picked up a used one the other day. When I get into the office tomorrow I'll see if I can get some numbers off of it and verify that it's indeed made by GAL. Best regards, Allan
Parent - - By ctacker (****) Date 12-07-2007 15:01
Allen,
I've been to galgage site and they sent me a catalog, didnt see anything like it, my fiance also bought me a large suitcase full of inspection gages from them, and nothing like it. unless I missed something, it probably isnt galgage!
thanks,

        Carl
Parent - - By hogan (****) Date 12-07-2007 15:09
i think what allen is refering to is on the cam type gauge
Parent - - By ctacker (****) Date 12-07-2007 15:59
I have 2 cam gauges, but that doesn't check how much convexity a fillet weld has, except for checking the throat and then the leg, it seems someone would come up with some type of contour gauge with a bunch of thin plates to get the contour of the weld,then you could measure the convexity!
Parent - - By aevald (*****) Date 12-07-2007 16:28 Edited 12-07-2007 16:30
Carl, I didn't see this post until I had already posted mine w/pictures. I now understand what you are getting at. Give me a little time and I will have a reasonable response for you. Regards, Allan
Parent - - By ctacker (****) Date 12-07-2007 16:40
Thats how i been doing it Allen, i just think some kind of contour gauge would be easier, at least for me! we get into some pretty tight spots, and getting the countour,getting out and measuring would be alot more economical from my point of view!
Thanks
  Carl
Parent - - By aevald (*****) Date 12-07-2007 17:11 Edited 12-07-2007 17:39
Okay Carl, I have a wild idea here. You have probably seen the profile gages that carpenters sometimes use when they are trying to fit around complicated coves, moldings, and other off-shapes. They are made up of all the like-length pins and pass through a plastic block or something of the sort, you push them up against the item you are trying to duplicate the profile of and WAH-LA a copy of that shape. You could then take your measurements from this profile. I wonder if you couldn't do the same with a slightly modified version for checking weld profiles. I have included a sketch for a possible better understanding of what I am talking of. Computer network is acting funky this morning hope I can get it to attach. Having technical difficulties will attach as soon as system is back up.  GOT IT TO ATTACH AND HAVE INCLUDED SKETCH   Best regards, Allan
Attachment: 891WeldprofileGage.jpg (25k)
Parent - By hogan (****) Date 12-07-2007 17:41
a little off topic but, the profile gauge works very well when performing UT shear wave. when you draw out your sound path and have an unusual connection (great for t, y, & k connections) it helps with correctly drawing your a and/or b surface.
Parent - - By ctacker (****) Date 12-07-2007 18:06
Allen, thats pretty close to what i was thinking, you'd think someone would have come up with one. i believe it would be alot more accurate for checking convex welds but your "plates" would need to be very thin,and made of spring material so as not to bend easily!
Parent - - By aevald (*****) Date 12-07-2007 18:21
I believe that some of the woodworkers versions are made of exactly the types of materials that you mention. I'm pretty sure the pins are of a spring steel or stainless steel and the "holder" or part that the pins slide through are fairly thin and some of their designs might allow for shortening to better fit your purpose. Regards, Allan
Parent - By ctacker (****) Date 12-07-2007 18:34
Thanks Allen, I'll check out some woodpecker shops and see if they might have something that fits the bill!
Parent - - By aevald (*****) Date 12-07-2007 16:19
Hello Carl, as hogan included in his response, it is on the G.A.L. gage - Bridge Cam Type. This particular gauge, as nearly as I can tell is capable of determining HI/LO, Depth of Throat, and angular degrees, it is also metric/standard scaled. I have included a number of pictures to further explain. Best regards, Allan
Parent - - By 803056 (*****) Date 12-07-2007 19:47
There is no way of measuring convexity easily. One method I would suggest is to measure the width of the fillet face (toe to toe) with a pair of dividers. Then, using your bridge cam, measure the throat.

Now comes the fun part, measure each of the fillet legs and make a sketch of the fillet weld drawn to scale. The diagonal distance from toe to toe should be equal to the dimension you obtained with the dividers. Now layout the throat dimension you obtained with the bridge cam. The difference between the line drawn toe to toe and the bridge cam is the convexity. 

Now you have to go back to the table in D1.1 to see if it is within the dimension permitted by D1.1.

Its convoluted, but I haven't got my gage design perfected yet, so until I do, you have the method described by aevald or my way (which is a pain in the neck). The bridge cam by itself will not provide the information needed. The technique I describe will work on skewed fillets as well as those in a perfect 90 degree corner (when was the last time you saw that?).

You can calculate the theoretical throat if you know the three sides of the triangle or you can sketch it out and derive a graphically solution.

I use a home made set of fillet gages for measuring skewed fillet welds. They're close enough for the work I do. They are within a 1/64th inch when checked against a set of gage blocks.

The sketch that is attached is help you figure out what I've tried to put into words. Sometimes the sketch is better than my descriptions.

Best regards - Al
Attachment: ConvexityMeasurement5-Dec-07.dwg (29k)
Attachment: ConvexityMeasurement5-Dec-07.wmf (10k)
Parent - - By ctacker (****) Date 12-07-2007 20:21 Edited 12-07-2007 20:27
I know there isn't an easy way, but the way i described,and the way Allen drew it up would make it an easy way.
you'd think it would be widely available like the rest of the gauges. I've got the skewed fillet gauge by galgage along with just about every gage they make!
Carl
Parent - - By 803056 (*****) Date 12-07-2007 20:30
If it was easy, any one could be n inspector!

Al
Parent - By ctacker (****) Date 12-07-2007 20:34
They would still have to spring for, and pass the exam :)
Parent - - By ctacker (****) Date 12-07-2007 20:52
Allen, i posted a couple pics of what my woman bought me for my b-day, I don't care much for the suitcase but the gauges are top notch! galgage sells this and smaller sets!
posted on a previous post in this thread
Parent - - By aevald (*****) Date 12-07-2007 20:55
Pretty doggone nice Carl. Regards, Allan
Parent - By ctacker (****) Date 12-07-2007 21:07
I thought so, can't tell my fiance i scrapped the case though, i keep everything in a smaller bag, along with a camera, some handbooks, markers etc.
Parent - - By 803056 (*****) Date 12-07-2007 21:14
Nice photos aevald!

I've used the same method you describe, but the wires of the profile gage were too coarse and the gage was too wide for many applications. I'm sure there are others available, I just haven't seen the right one yet.

Best regards - Al
Parent - - By aevald (*****) Date 12-07-2007 21:18
Hello Al, and thank you, after finally understanding where Carl was coming from, it did get me to thinking and I am a bit surprised that there hasn't been something available that might fit this bill. Opportunity knocks? Regards, Allan
Parent - - By ssbn727 (*****) Date 12-08-2007 03:26
Now all someone has to do is contact G.A.L. Gage with the profile gage design, and see if they will want to buy the design - Capish??? :) :) :) How about it Al???

Respectfully,
Henry
Parent - By aevald (*****) Date 12-08-2007 03:37
Hi Henry, I'm drafting the contract as I reply! They'll likely be knocking my door down for the rights and yes, just in time for Christmas. On the other hand, the woodworkers will probably be sending me a writ to appear on charges of patent infringements and I'll lose everything I have. Merry Christmas and Best regards, Allan
Parent - - By tab_1999 (**) Date 12-11-2007 17:43
Al,

Just to clarify, If I follow the 3 items noted I have an acceptable weld if the minimum is met?
If the design specifies a 5/16" Fillet and the resulting weld is 5/16" (vert measure ) and the horiz. or lower leg is 9/16" which creates an off-leg Fillet, its ok?
I also run across single pass 1/4" FW's "Specified" and end up with a1/2" or larger multi-pass FW weld with regularity.
Should the only concern I have is if the plate/materials are warped or somehow make the item not fit-for service? ( providing there are no visible discontinuities/defects )
Thanks

What I am really asking is, how do other folks handle welds that grossly exceed the specified requirements of a Fillet Weld?
Parent - - By 803056 (*****) Date 12-11-2007 19:01
Hello Tab;

Most welding standard do not address over sized fillet welds. That being the case, as long as the minimum leg lengths are at least equal to the size specified on the drawing, all is good with the world. The as-built weld is at least as strong as the designer requires. Likewise, provided the weld length is at least as long as the length specified, all is well. The weld will still be at least as strong as the desigener needs.

The concern is, larger welds usually result in increased distortion. However, if the larger weld does not result in unacceptable distortion all is well.

Best regards - Al
Parent - - By tab_1999 (**) Date 12-11-2007 20:34
Thanks Al,

I appreciate your support.

Thanks
Tom
Parent - - By 803056 (*****) Date 12-11-2007 22:33
Hey Tab, did you remove one of your posts?

The QC inspector's responsibility is to apply the existing acceptance criteria and accept or reject work on that basis.

If there is an issue not clearly addressed by the welding standard (or code), QC should bring it to the attention of QA or other upper management (such as engineering). If after QC's case is heard, engineering and other interested parties agree, they can revise the acceptance criteria provided it is no less stringent than that imposed by the customer's requirements (or the applicable code with legal standing).

In no situation that I can think of should the CWI/SCWI, acting in a QC function, unilaterally change the existing acceptance criteria. The CWI/SCWI acting as a QC inspector can use the applicable code or standard, he can apply it, but no where does it say they are in a position to interpret the code or standard. The only group that can provide an official interpretation of the code is the code committee.

The bottom line is that fillet welds with unequal legs or fillet welds that are larger than that specified are not prohibited by most welding standards and codes. The QC inspector's personal opinion or bias doesn't count until the acceptance criteria is changed by management.

I can't recount how many times I've heard inspectors say, "I don't care what the code says, I don't like it and I'm not buying it!" Usually those infamous words are heard just before the inspector is handed his "pink slip".

Best regards - Al
Parent - - By tab_1999 (**) Date 12-12-2007 13:28
Hi Al,

Yes, I removed a post ( I thought before I even posted it )
I work on a Nuclear site in the QA/QC group. We have Structural Engineers that write specifications to various standards, and they do very well.
There are times when the (P.E.)Engineer replaces portions of the specification by stating that a section or sections of AISC will take the place of certain sections
of AWS and notes the chapter & verse. The company I work for is an International organization is in the construction business of Engineering, Procurement and Construction.
I typically get involved in whatever phase is needed. I guess my welding /inspection side impacts the procurement side by knowing that if a manufacturer , as a rule of thumb, overwelds structural fabrications, they would have to increase their cost per ton etc. to capture the wasted consumables and time. I'm sure it impacts them from a competitive standpoint. I just like to be proactive in finding ways to help all parties mesh. Sometimes specifications need to be a little "tight" to help ensure overall project costs stay aligned with funding.

Thanks again  Al
There is no shortcut to anyplace WORTH going!
Tom
Parent - By hogan (****) Date 12-13-2007 17:02
the only issues i see are if it is over sized , in extreme cases, there might be an issue with heat input. also from a production standpoint, it's not profitable.
Parent - By David Lee (*) Date 12-16-2007 01:53
The whole concept of an unequal leg size is based on a fillet weld. the criteria is in D1.1 section 6. In my belief this is based on improper angle of the electrode being used. In which may result in incomplete fusion. Again this is why the code will limit under run. To say bigger is better ?
Not so although the books allow it. Incomplete fusion at the joint root or in the fusion face is not acceptable!
Up Topic American Welding Society Services / Technical Standards & Publications / Unequal leg lengths per D1.1

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