In recent CWI work another company insisists that I was checking bead height on a fillet weld wrong.I don`t think so.They told me that I should check from the top plate,but I insisted that this is not the correct way to check the bead height.The bead starts from the bottom and is measured to the top,I insisted.Who is right?
Edited....It's Monday ;>)
By bead height I'm guessing you're talking about the leg length not convexity or concavity, in which case you can check both leg lengths with single or separate measurments. What kind of gage are you using?
The Gage they give me is thier gage that just has a 1/8 cutout in it that says max bead height 1/8 so when it protrudes over the top 18 gauge plate somewhat it always fails in my opinion ,but this company claims it is checked from the top plate.I have told them that thier is nothing in thier literature that shows you to check the bead height from the top plate so I run the gauge along the bottom plate and if the convexity protrudes over .125 then I fail it.Wrong/Right?
http://www.qtm.net/~galgage/automat/
Is this gage similar to what they issued you to use? I have one of these although I have rarely ever used it. Most if not all of our butt joints are ground flush (no reinforcement to measure) and the fillets are checked with the fillet weld gages.
Now what code are you working to? I ask this because 18ga materials fall into the D1.3 and it has different acceptance criteria than D1.1.
John Wright
Could you describe the joint to us. From your original post I visualized either a T or a corner joint with the overhead member (top plate) in the horizontal position. Now that you mentioned bottom plate I’m confused.
Is this gage some sort of a go / no-go device or is it a Palmgren gage like the one John linked to? And are you only measuring convexity (the distance between the theoretical throat and the actual throat) not leg size? Is it a multi-pass fillet? Sorry for all the questions, I’m breathing thin air today.
After all that, I did not make my point....to determine the theoretical throat, multiply the fillet leg size times .707 (cosine of 45*).
I too am not sure what you mean.
As thirdeye mentioned, the common fillet guages can measure both legs at once. The single arc measures one side and the scribed line measures the other. It doesn't matter which way the guage is held, it can be read in both directions.
Assuming a fillet on a joint fitted at 90 degrees, the intent is to determine the largest triangle that could be drawn inside the weld cross section.
For a convex faced, measure the distance from the root to the toe of the weld on both legs.
For a concave bead, use the double arc side of the gauge to determine the throat dimension and ignore the apparent leg dimensions.
The guage uses the intersecting planes of the 2 legs as the reference plane.
Having said all that, I really can't see how anyone could measure from the "top to the bottom." You might want to reference AWS B1.11 -"Guide to the Visual Inspection of Welds". Mine is the 1988 version but the diagrams on fillets make measuring clear.
Chet Guilford
I check leg length on both planes one at a time then check the throat.
Hope this helps,
Brian J. Maas
http://www.qtm.net/~galgage/7piece/
Here is a link from the GAL Gage Co. showing the fillet weld gage most of us are accostumed to using.
http://www.qtm.net/~galgage/skewt/
And this is a link showing a fillet weld gage that can be used on skewed joints where the plates are not welded 90 degrees to each other.
HTH,
John Wright
Hey John,
I have the skewed fillet gage and calculator, but it says "Bechtel M&QS" on it instead of "G.A.L. Gage." Does that make mine a collectible?
It might! My understanding is that G.A.L. Gage bought the rights to the guage from M&QS.
Marty,
That flew right over my head and I didn't catch it when I read it hurriedly the other day. How long have you had that set of gages? Are the gages still ledgible? The set I use here at work are fairly new, and it's getting hard to read the etchings on the regular fillet weld 1/4, 5/16, and 3/8. Someone liked the old set I had better than me I guess, they were missing off my desk :(
John Wright
We also buy gages from GAL. On the blade type that John linked to I order the ones with marking on both sides, it makes them much easier to use especially if your on a ladder. My favorite ones are the adjustable fillet gages (they have a little slider for unequal leg welds, and measure in 1/32").
PS. In looking at a new set of blade gages, that still have the instructions, it says to place the blade on the horizontal member. (I think this is just to explain the use). Anyway, maybe someone is following the instructions to the letter?
Here is a page with some info that may help. http://www.weldinginspectionsvcs.com/FilletWeldgage.htm
Do check from both plates. Minimum throat can be checked from either.Both legs should meet the minuimum size. If one is small the throat will not be of correct size and if thebead isconvex, this will not showup with the throat measurement. For that reason, both leg sizes should be checked.
GA
The weld on a lap joint is sticking way above the top plate,the gauge they give me is thier gage that says 1/8 max bead height.They say it is checked from the top plate on a lap joint of two 18 guage pieces I say no.Simply what is right.Noone has answered this out of all these replies????
I was never sure what "their gage" looks like and was trying to get you to describe it better so we could get a handle on what it is you are using to measure these welds with. Without this information, I'm not sure if the gage is being used correctly or not. Also please state what code you are working to, as that directly affects the criteria that you would use to accept/reject these welds by.
Is this gage a "go/no-go" type gage that the company has fabricated and given you to use?
John Wright
I would agree that weld size is usually determined from the bottom plate in a lap joint of structural steel members. But AWS D1.3-98 states...
"2.3.3.2 Leg Sizes. Leg sizes of lap joint fillet welds shall be equal to the thickness of the thinner sheet steel (see Figure 2.7.) The leg size of the T-joint fillet welds shall be equal to th thickness of the thinnest sheet steel (t). (See Figure 2.8)"
"6.1.1.2 Minimum Reinforcement. The weld shall have a minimum reinforcement of 1/32" (1 mm) for all square groove, arc spot and arc seam welds."
Nothing seems to have a maximum reinforcement limit. The weld size is limited by the thickness of the material. So it would appear that your customer has their own inspection procedure and acceptance criteria. If that is what they want then it seems simple to do it that way. They may have a reason that they only want 1/8" reinforcement. Unless you have a good reason to not check it that way, I would do it their way. Hope that helps.
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