AWS type weld gauge

Date 10-09-2009 12:01

I have not seen the gauge, but I know that AWS D1.1 has maximum convexity limits for fillet welds in Figure 5.4. These are based on the width of the weld face or individual bead width. MAX CONCAVITY - I can only guess this would apply to fillet weld throat dimension.

By CWI555

Date 10-09-2009 12:01

G.A.L. Gage http://www.galgage.com/ has a video on it. The first link explains the AWS gauge toward's the middle of it.

http://www.youtube.com/watch?v=vzYj0qsLbVY

http://www.youtube.com/watch?v=WT1wzeXs3Yw&feature=related

Regards,
Gerald

By welderbrent (*****)

Date 10-09-2009 14:40 Edited 10-09-2009 15:37

Zambrota,

Gerald gave very good links worth the time to check out. And my comments would be evident to those who go there. But, just for the record, an AWS Gage is an abbreviation for 'Automatic Weld Size' Gage. So called by GAL Gage. Other companies make them as well. They have several features similar to a bridge cam. They go into a 90 degree corner and give a throat dimension of a fillet weld, calibrated for both concave and convex. They also can be used to check the weld reinforcement of the 'crown' of butt joint groove welds. Mine also has different 'thicknesses' of the two legs for checking root gap.

Personally, I seldom use one. I prefer the Bridge Cam supplimented with Fillet Weld Gages. Let's me do much more and I believe them to be 'more' accurate. At least I feel more comfortable and consistant in my evaluations using them. Especially since most all requirements are for leg size not throat dimension.

Have a Great Day, Brent

By flamin

Date 10-09-2009 15:45

I prefer the Bridge Cam gage over the AWS gage too. It's just my personal preference. However. G.A.L. makes a miniature version of the original (bridge cam), which comes in real handy in tight spots. It does cost a little more, but it's worth it IMO.

Jason

By Superflux (****)

Date 10-09-2009 16:59

True.... Fillet Welds are called out by leg length. But, you must know how to measure the throat to accept or reject its size. If the print (symbol) calls for a one-inch fillet weld, just because it has a 1-1/16" leg length does not make it an acceptable (due to excess concavity) one inch weld by throat. The 1" weld must have .707" throat.
Since I've never used the "AWS" gage by G.A.L., I recommend a full size and miniature set of fillet gages and proper instruction on their use (ie. fillet weld measurement and gaging). Any well stocked Welding supply store will carry the Anchor or Fibre Metal brand fillet gage set (these are a "go/no-go" type device). The Cambridge gage (I guess I'm dating myself since they are Bridge-Cam now) is a bit more complicated in its calibration (yes they must be checked for calibration), use and interpretation of data obtained.

John

ps. good luck on your cracking problem

By zambrota (**)

Date 10-10-2009 08:09

Thank you Gerald, Brent, Jason and John. I appreciate your effort regarding AWS gauge. I watched G.A.L videos before, but it is still confusing. I am not clear what is actual reading. Is it fillet weld throat thickness measured by gauge or some calculated value? As you know, actual gauge measurement is one thing and actual reading is another thing. I could agree that fillet weld throat is measured but G.A.L. video shows that reading on "MAX CONCAVITY" scale is the effective weld size for concave fillet weld. I guess it is the size of concave fillet weld (theorethical leg length). On the other side the reading on "MAX CONCAVITY" scale is shown on video as permissible convexity for the convex fillet weld. What does it mean? Is permissible covexity reading of actual throat size or it is fillet convexity as defined by AWS D1.1 standard (i.e. the difference between actual throat size and theoretical throat siza)? Do you know what I mean? I need somebody to answer (using simple words and AWS D1.1 terminology) two questions:

1) "MAX CONCAVITY SCALE" ... what is actual measurement ( ?) what is scale reading ( ?)
2) "MAX CONVEXITY SCALE" ... what is actual measurement ( ?) what is scale reading ( ?)

Thanks again

By Superflux (****)

Date 10-10-2009 17:39

zambrota,
I am available to come to your home or facility and provide you with in depth training of Visual Weld Inspection techniques, measuring and use of gages.

By 803056

Date 10-12-2009 17:32

The way I handle it is as follows:

I measure the face width and covert that to an equivalent isosceles right triangle to determine the approximate leg size.

Comparing the ends of the gages used to measure concave fillet welds, I select a larger fillet gage that has a throat dimension that is larger by the amount permitted by the code.

The example in the following sketch has a 3/8 inch face width. The equivalent fillet size is about 1/4 inch. In this case, 1/16 inch is the amount of convexity permitted by AWS D1.1. Place the 1/4 inch gage in your palm. Looking at the end used to measure concave fillet welds; lay the larger fillet gages over the 1/4 inch gage until you find the one that is larger by the amount permitted by the code. In this example, the 3/8 inch gage seems to be the closest approximation. The 3/8 inch gage has a throat dimension that is about 1/16 inch larger than the ¼ inch (concave) gage.

Check the actual convexity of the weld using the end of the 3/8 inch fillet gage used to check concave fillet welds. If the fillet face forces the concave end of the gage away from either the butting on non-butting member, the convexity is too large and the weld is rejected.

If this explanation is difficult to follow, the embedded sketch may help.

Best regards - Al

ConvexDeterminationFilletWeld12-Oct-09Model1.jpg (178k)

By zambrota (**)

Date 10-12-2009 21:51

Thanks Al,

I like your practical approach. Does your theory work for both concave and convex fillet welds. If yes, why does AWS gauge have two separate scales, one for MAX CONVEXITY and another for MAX CONCAVITY? Does the fillet weld throat measurement depend on shape of weld surface? Do you have any experience with AWS gauge?

All the best

By 803056

Date 10-13-2009 03:26

The standard leaf type fillet gage has two ends, one for measuring the leg dimension of the convex fillet weld and the other to measure the throat of a concave fillet weld. The throat is the minimum permitted not including the 10% under-run of the overall length allowed by D1.1.

The A.W.S. gage is a "knock-off" of the Palmgren gage that was the grand daddy of our "modern day" gages. It was required by some of the military welding standards back in the "old days" before the standard leaf type fillet gages were available.

Like the "Cambridge gage" and many other multipurpose gages, it does a lot of different things, but none of them very good.

An "inspector" that only carries a single multipurpose gage is like a half-assed mechanic that carries nothing more than an adjustable wrench. A skilled inspector, like a skilled tradesman, carries many tools, each with a specialized purpose.

Now that I have offended many of my colleagues, I can go to bed and sleep a little sounder. Anything for a laugh! :0

Best regards - Al

By CWI555

Date 10-13-2009 09:36

'An "inspector" that only carries a single multipurpose gage is like a half-assed mechanic that carries nothing more than an adjustable wrench.'

Out of curiosity, does this logic apply to the 'inspectors' who believe they have calibrated eye balls and need no gages? Or are they an upstanding member of the FC 2002 committee?

By 803056

Date 10-13-2009 13:31

They, like me, are "Charter Members in Good Standing" of the FC2002 and are typically identifiable by the magnifiers with the small compass built-in to the handle they carry at all times so they don't get lost on the "Big Jobs". ;)

Best regards - Al

By jwright650 (*****)

Date 10-13-2009 13:49

I thought the compass was for locating the column faces, so you could identify which face of the column you were looking at, on the site plan....LOL

Ever get turned around on the jobsite Al wondering which way the building was oriented on the lot?...LOL<sheepishly raises hand> But my excuse was that I was looking at hanging frames that I had detailed and the erector called in telling me that they won't work. So I go looking for the piece marks and eventually figured out that the erector had tricked me by placing the wrong frames over the wrong openings...LOL After I figured out what he did, I asked him what was the problem with my steel that caused me to drive 14 hours straight to get there for this huge emergency? He said that the frames won't fit.....then I showed him that he had them hanging on the wrong side of the building, and that they indeed fit in the locations that they were intended for. So he had to cut all that mess down and repair all of the cuts and splice back portions of the TS and L hanging frames where he had chopped off, before the block mason caught up and then he had a huge ticket for holding those guys up until the EOR would sign off on that mess.

By 803056

Date 10-13-2009 15:23 Edited 10-13-2009 15:27

To locate the north face of the column you have to look for the green moss.

I had one erector put the building up 180 degrees out of sync with the drawings. Then he couldn't figure out why the building had a large overhead garage door opening toward the "lawn".

Back in the "70's" while I was working in Mississippi I had a self standing elevator tower that tied into the building at the tenth floor. They couldn't get it plumbed so they told me, "Hey Yank, go plumb the tower, the other ganged said they had problems with it."

So I asked for a set of drawings so I could check the steel. "You don't need the drawings to plumb the tower, just put a couple of cables to it!" was the response.

I checked the tower with a transit and saw that it was 6 inches out of plumb. I figured if the other gang had problems, it could be that there was a couple of mislocated pieces causing it to be so tempermental. I went into the office during lunch and pulled the drawings. Low and behold, half the members were in the wrong locations. When I mentioned it to the foreman his reply was, "They're all the same, it don't matter!"

I asked him if they were all the same, why did they have different piece marks?

After two days of changing out the iron and relocating the members to the right location, the tower nearly sprang into plumb! Funny how that work!

By the way, is there an easy way to shrink/scale the embedded sketches so it is visible without having to move the cursor across the page?

Best regards - Al

By Superflux (****)

Date 10-13-2009 16:31

zambrota,
The fillet weld measuring procedure outlined by Al is in fact the method commonly used by many of us. The problem of evaluating unequal leg lengths vs. throat comes in to play. Everyone thinks QC and Weld inspection is simple and a no brainer, but this misconception comes mostly from those with "no brains"! The Automatic Weld Size is just convenient with its Max and Min functions. To try and answer your post further...A fillet weld is sized by a relationship between leg length and its throat..ie volumetric in nature. Too much concavity and it is of insufficient size to acccomplish its designed function. Excess Convexity and it is;
1) an unacceptable stress riser
2) unable to determine fusion or slag entrapment at the toes and ...
3) JUST PLAIN UGLY!

I lost my AWS gauge years ago and have used other tools for measuring fillet welds. I consider the Pocket size or Full size Bridge Cams a "must have" if you are limited to only one tool in a QC Tool Kit. I pack along a Tote bag with dozens of gauges, calipers, micrometers etc. and was called "Inspector Gadget" on one particular longterm project.

Hope this helps.

BTW Al, I could rebuild an 8N tractor with 2 crescents AND channelocks.. no self respecting "shade tree knuckle buster" would dare attempt any job with only one crescent wrench!!!

By 803056

Date 10-13-2009 19:00

Thank you for supporting my position that no self respecting mechanic would undertake a monumental repair task with only an adjustable wrench. Multiple wrenches and a pair of pliers is in fact a necessity. I rest my case Your Honor! ;)

By the way, there isn't any acceptance criteria for ugly.

Best regards - Al