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Up Topic American Welding Society Services / Technical Standards & Publications / Larger than 1" dia shear studs.....
- - By jwright650 (*****) Date 11-14-2008 13:35
What are you guys doing when you run into studs that are larger than 1" and you don't have equipment that will shoot them(ours shoots up to 7/8") and need to fillet weld them?.....Are there any guidelines as to how much weld is required when the diameter is in excess of what is in Table 7.2? Paragraph 7.5.5.4 is no help.
Parent - - By jwright650 (*****) Date 11-14-2008 13:38
Thought that some of you bridge (D1.5) fabricators would know this....this is the first job where we had embeds with studs this large, so I haven't had to cross this "bridge" before. BTW, I don't have a copy of D1.5 to review, should that address this issue.
Parent - - By CHGuilford (****) Date 11-14-2008 14:11
Our usual technique for shooting large studs is "When in doubt, sub it out."

John, I'm writing this on the fly - I think you'll find D1.1 and D1.5 have no practical difference when dealing with studs.
Parent - - By 803056 (*****) Date 11-14-2008 15:52
I would think that from a practical standpoint the circumferential fillet weld would have to be large enough to develop the full strength of the stud and it would have to be deposited with a low hydrogen electrode or low hydrogen welding process. The flux pellet would have to be removed and the end of the stud ground to be square and bear against the substrate. Proper sizing of the weld would be the engineer's responsibility. Likewise, the EOR would have to be agreeable that the procedure and sizing was acceptable for the application.

Best regards - Al
Parent - - By jwright650 (*****) Date 11-14-2008 16:03
I guess that I'm a bit taken back a little that no one else seems to fillet weld these. I think we only have a couple hundred to weld, but I'll have to dig a bit further to see just how many we are up against. I hope the estimating/sales people covered this item with enough money, no one here in the shop was notified until after the contract was a done deal. We just had a job go through here recently where we had 1" studs welded to embeds. All these heavy studs are a new item for me. I wonder if this is going to become a thing of the future or is it just a design whim that is passing through?
Parent - - By mountainman (***) Date 11-14-2008 17:49
we do alot of fillet welding of studs if our stud gun station is to packed, but 7/8 is the largest i have ever encountered. talk about engineering whims, how about a call-out for 3/8 dia. studs to 1" plate for embeds. can you say WTF? believe me i have seen it.

JJ
Parent - - By hogan (****) Date 11-14-2008 17:59
We recently had a job that required 3/4"x5 studs to 3x3x3/16" tube steel. I could not get them to shoot correctly and ended up fillet welding them.
Parent - - By mountainman (***) Date 11-17-2008 20:27
i would imagine you had to take extra time and straighten the dang things when you were done? that's always a pain in my butt.

JJ
Parent - - By swnorris (****) Date 11-18-2008 21:24
hogan,

The minimum allowable thickness to weld a 3/4" diameter stud to is 1/4".
Parent - By mountainman (***) Date 11-18-2008 21:50
Scott, i have run into situations similar and sent RFI's to bring the code req's to light, but each time the engineer stuck with their original call-outs. and most times we indeed had to end up fillet welding them because we couldn't get desirable results shooting the studs.

JJ
Parent - By hogan (****) Date 11-18-2008 21:54
swnorris,
We submitted an RFI as mountainman has mentioned.
Parent - By Bob Garner (***) Date 11-18-2008 22:27
Right on swnorris, as per D1.1 Section 7.2.7!

There is no excuse for an engineer to not specify the right size stud for the base metal thickness.  Bounce it right back to him with an RFI as everyone suggested.  And keep track of the hours to backcharge him.

I is an engineer and I totally lose my patience when my peers don't take the time to engineer it right!  You tell the engineer that designed this that I'm gonna come and kick his butt if he can't take the time to look this up and do it right.

Bob (Grrrrr!) Garner, S.E.
Parent - By jwright650 (*****) Date 11-14-2008 21:47
Well guys,

We ended up getting our engineering people to look at this for us...they are working on it as I type.

Good thing, because we start working on them first thing in the morning...LOL

Thanks for all the replies...it's good to have an experienced crew like you guys to bounce this stuff off of.
Parent - - By hogan (****) Date 11-14-2008 15:49
John,
We use a local contractor that has a mobile stud welding set up for large dia. studs. From what I remember he can shoot up around 2000 amps.
Parent - - By jwright650 (*****) Date 11-14-2008 15:57
I think our people want us to tackle this one in-house. We even looked at a machine large enough at one point and dismissed the idea when the quote came in.
Parent - By welderbrent (*****) Date 11-14-2008 16:36
John,

I just went through this big time doing a Mini Storage facility that need more studs than I care to remember.  When you weld the the processes listed in 7.5.5 and the fillet weld requirement of 7.5.5.4 it sends you to the larger of either Table 7.2 or Table 5.8.  Depends on rather your stud or base material needs the larger fillet weld listed.  A 1" stud would go to a 3/8 fillet per Table 7.2.  Don't think at that point that you would have to go any larger because of the base metal thickness.

After pouring over the code books and consulting with half a dozen other inspectors we re-ran our 2"pipe to plate test for all position just to be on the safest side of any hard nose city inspector or a CWI who didn't know what we had gone through to get to that point.  Made us good for field and shop in any position that may have been technically missed with other certs.

Hope I was able to help.

Have a Great Day,  Brent
Parent - - By jwright650 (*****) Date 11-15-2008 14:13 Edited 11-15-2008 16:31
UPDATE:
OK...found out exactly what we were up against...they are not studs, but couplers. These couplers are beveled to accept a partial pen weld with a 3/8" fillet reinforcement. Got the sketch from the engineer this morning.

edit: Marty,
These are similar in design to what you are talking about.....They are beveled on one end for welding, and internally threaded to accept a large diameter rod/stud...and the ones that we have to use on this job are 1.25" and 1.63" outside diameter.
Parent - By MBSims (****) Date 11-15-2008 15:31
We used to fillet weld A307 nuts on embed plates.  Bolts were threaded in for shear studs and tack welded once the plate was placed on the forms/rebar.  They would also have holes drilled at each corner (~3/16") for tie wire or nailing to the forms.
Parent - - By hogan (****) Date 11-17-2008 15:57
Now is the coupler a pre-approved base metal?
Parent - - By jwright650 (*****) Date 11-17-2008 18:26
Yes, they are made from A36

http://www.barsplice.com/index.html
Parent - - By swnorris (****) Date 11-18-2008 21:27
Last year we did a bunch of those couplers.  They took #10 and #11 rebars.  I was concerned about the chemical composition of the couplers, but found out that they were A36 as you said.  Seems that I had a problem with determining the min. fillet weld size on the couplers.
Parent - By jwright650 (*****) Date 11-18-2008 21:37
Re: weld size
Scott, I was handed a sketch with the weld size shown, so that is what we went by. Our inhouse engineer supplied the sketch, and he just developed enough weld to match the bar that these were attached to. I don't know who is swedging the part onto the rebar that screws into the coupler that we welded on, but they mentioned using a 430 ton press in the literature...
Parent - - By ctacker (****) Date 11-14-2008 22:46
We used to rent a machine when we needed to, if there are enough studs to make it worth it.
we own a nelweld 6000 dual gun stud welder that can shoot 3/16" to 1"and we are lucky to shoot 1000 studs a year, what a waste,LOL
Parent - - By swnorris (****) Date 11-18-2008 21:42
John,

The strange thing for us was that we had to screw the rebars onto the couplers, and then weld the rebars to the couplers! I'm thinking.... why not eliminate the couplers and the threaded rebar, and just weld the rebars directly to these 2" thick embeds because as you know, those couplers 'aint cheap.  I tried and tried to get this changed, but I couldn't.  
Parent - By jwright650 (*****) Date 11-18-2008 21:48
We have the swedged type and the mechanical type(mech has several set screws with a TC type head that wrings after they get tight).
Up Topic American Welding Society Services / Technical Standards & Publications / Larger than 1" dia shear studs.....

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