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Up Topic Welding Industry / General Welding Discussion / welding a structural steel bolt.......
- - By bellaru (*) Date 04-27-2007 03:02
i know that it shouldn't be ,,,,,,,,but what would be the best way to weld a grade D medium crabon , quenched and tempered , 170,000 psi nut to a peice of A36 1 inch plate....preheat,,postheat,,,,filler metal........ect..........?

i understand that the nut is going to go to sh*t , as far as the mechanical properties go , but it has to be done..........??????
Parent - By G.S.Crisi (****) Date 04-27-2007 15:38
I understand you pefectly, Bellaru.
Back in my days of erector engineer we had to do the same. By the way, I was a "just out of school" engineer and that was my first job.
The company I worked for was erecting two Riley Stoker boilers for a small thermal power plant.
The anchor bolts were already inserted into the boiler foundations. We put the boiler baseplates leaving 1 inch of grouting clearance with the top of the foundations. The correct clearance was assured by shims.
Then we erected the boiler supporting columns and screwed the nuts onto the anchor bolts. The anchor bolts tip barely got to the middle of the nuts. In fact, as we realized later, the anchor bolts had been installed some 3/4 inches below the correct elevation. Civil contractor's fault.
What to do? Riley's erector engineer (Mr. Joseph Tasker, a 60 years old man who taught me, a young and unexperienced engineer, a lot of things and to whom I'm still grateful), told us to fill with weld the holes left in the baseplates by the too short anchor bolts.
45 years have passed and the boilers are still there, old but still working fine.
So, my advice is: Go ahead, Bellaru, and don't bother to what the too theoretical metallurgists may say .............
Giovanni S. Crisi
Sao Paulo - Brazil  
Parent - By jwright650 (*****) Date 04-27-2007 15:55
As far as being able to go back on the fastener mfg on a failure should one occur....they won't stand behing their product once you weld it.

I asked one of our bolt vendors this question one day about tack welding a nut to the backside of an inaccessible joint...knowing full well what the answer would be, and they simply said that there are so many variables to take into consideration that they could not fully answer the question. They simply suggested looking for an alternate method of fastening or connecting the joint.

Has someone designed this joint with the full allowable design strength of that fastener? If so, I would think hard about this before you weld it. To cover yourself, I would get someone else to sign off on this like the EOR who is ultimately responsible for the job.
Parent - - By TimGary (****) Date 04-27-2007 20:31
Not knowing what the application is, or how much stress will be on the weld.....

I would stick with the less is more theory.
If you can, just weld a single pass with 6010. I would make a separate weld or tack on each hexagonal side of the nut. That way if a weld cracks it would be less likely to propagate around the entire perimeter.
Parent - By ZCat (***) Date 04-27-2007 22:29
7018. 6010 is too brittle for welding bolts. Any time we ever built screw dogs, 7018 held the best.
Parent - - By downhandonly (***) Date 04-27-2007 22:30
could you tack a piece of square stock up against one of the flat sides of the nut to stop it from turning. or is the weld to hold it up in place?
Parent - By DaveBoyer (*****) Date 04-28-2007 04:03
I think I would weld a nut on a chunk of scrap first,  small tack welds on oposite sides [2 welds, minimal heat input to get a sound weld] then break it off with a sledgehammer and see if the weld failed or if the nut broke. If the nut breaks I think I would post heat to about 700 F and try again.
Parent - - By darren (***) Date 04-28-2007 04:09
if you could explain application a little better or send pic it would help.
is epoxy to hold it in place a solution?
darren
Parent - - By 803056 (*****) Date 04-28-2007 15:58 Edited 04-28-2007 16:03
Once the nut is tack welded, the question is; what mechanical properties?

We all know the problems that can be encountered when welding a high strength alloyed steel. The materials properties are controlled by the rate of quenching from the autenizing temperatures and the tempering temperature. The same conditions can't be ensured when the nut is welded to a plate.

However, in this case we do not know what the design of the connection is requiring. Are the connections required to be simply snug tight? Are they in a slip critical application? Only the engineer can answer those questions.

In many applications the nut simply keeps the bolt from falling out of the hole. Snug tight is all that is required. Hence, the ability to develop a tensile preload in the bolt is not necessary. Welding the nut, while not recommended, really isn't going to affect the connection or the ability of the nut to keep the bolt in place. The nut, in theory, could be replaced by a cotter pin through the bolt shank.

On the other side of the coin, a connection that is "slip critical" depends on the bolt and nut to clamp the connection tightly together. The friction between the faying surfaces of the connection is developed by the tensile preload of the bolt and nut. If the nut is "softened" by the heat of the welding operation, the full clamping force may not be developed and the connection will "slip" when it is loaded. The "softened" nut may strip before the full preload is achieved. If the nut is austenized and quenched by the welding opperation, the nut may become hard and brittle. It may crack when it is tightened and again the full preload may not be achieved.

I haven't tried this, but it may be interesting to make a mock up of the application you have. Replicate the connection using the same materials and thicknesses. Tack weld the nut (using the same procedure you will use in production) to one of the pieces that has the same thickness and cooling affects expected in the actual application. Put the assembly in a tension testing device (Skidmore/Wilhelm machine) and tighten the bolt and nut to see what happens. You might have the EOR witness the test so that he/she will be more comfortable "signing" off on your request to tack weld the nuts.

I would use a E7018-H4R to weld the nut and make sure the nut is degreased before welding it. You can apply some lubricant after the welding is completed. In this case, it isn't a question of the weld breaking, it is a question of the nut cracking due to the introduction of atomic hydrogen into the HAZ of the nut being welded. Check out the thread on low hydrogen electrodes that has been running for the last few days.

Good luck - Al
Parent - - By bellaru (*) Date 04-29-2007 16:07
Al , i am the one who started the low hydrogen thread,,,,anyway ,the design wolud be "Tension",,, they want to weld the nuts on to a massave peice of A36 thats embedded in the groung,,,,,,,,screw in the (lifting eyes),,,,,,and pull it out and up,,,,,about 90ft............there will be alot of tension on these nuts......they could bust off even before they get this thing out of the groung,,,,,,or worse up in the air.......

i mean , these nuts will not be the same once they've been welded,,,,,,,,crack or break,,,,,,pull-out- either from the base metal or thru the threads.....i just wouldn't trust it......

what , just pre-heat to 300+ and lo/hy it on there,,,,,,,,,,,,,,what filler strength group would be used..........base metal 50,000psi,,,,,,,,,nut,,,,150,000psi..........
Parent - - By downhandonly (***) Date 04-29-2007 16:44
why not weld lifting lugs onto it?
Parent - By TimGary (****) Date 04-29-2007 17:18
Amen Downhand...
Welding nuts on for lifting would be crazy...
No way would I let my crew do that.
Talk about an accident waiting to happen...

Tim
Parent - By Joseph P. Kane (****) Date 04-29-2007 17:32
It sounds like you are knowingly making a very significant engineering design decision.  Unless you are the engineer of record, you sound like you are knowingly performing engineering without a license, and with some perceived risk to the public or to your co-workers.  Pease re-consider before you hurt someone.
Parent - - By 803056 (*****) Date 04-29-2007 19:16
Hello Bellaru;

Answering a question in a thread like this is dangerous because we do not have all the information we need to make informed decisions or offer meaningful suggestions.

This application needs to be reviewed by an engineer that can make a proper assessment of the conditions and the loads that are involved.

From your description, the plate is embedded in earth or concrete. I'm not sure which. We do not know the size, thickness, or weight of the "massive" A36 plate. We don't know if one, two, three, four or more high strength bolts will lift the plate saafely even if the nuts were welded properly.

I like the suggestion that lifting eyes (lugs) be welded to the steel plate, but again, more details must be known so that the proper size lifting eyes can be welded to the plate.

I was witness to a serious accident several years ago. A contractor was in the process of removing a cement silo. He was told that the silo was empty. Without checking the contents of the silo, he hooked the crane to the silo and proceded to cut the supporting steel away. When sufficient supporting steel was cut, the load transferred to the crane and picked the front of the crane off the ground. The crane operator released the load which hit the ground with a roar. Needless to say, there was no silo left to relocate and luckily no one was killed or injured.

The price your employer pays an engineer to design a safe pick is very inexpensive in comparison the the peace of mind your company will be buying.

Best regards - Al
Parent - - By bellaru (*) Date 04-30-2007 01:53
thats what i say.......no way........i even mentioned the lifting eyes myself.......but the guy in charge say's ,,,,go ahead , use the nuts and start lifting it up just out of the ground , if none break off , then take it all the way up...........

i would never do this,,,,i write alot in this forum and just wanted to run down to you guys some "more" of the stupid , unsafe construction method's used..........

i myself have ended up welding a nut in some way or another  , or tacking it to the back of a hard to reach sitution , and it ends up working out ok , but not this  , this is a crazy operation.........

by the way , the plate is 10ft square/ 4 inches thick and has a chunk of W14x370 about 3ft long still welded to it,,,,,,,,,,,,they want to just weld on as many nuts as its going to take , and start lifting.........maybe i should take my video camara with me .....

there guys are rock quarry workers,,,,,,,,,they look real good untill OHSA or MSHA leaves , then its back to crazy unsupervised work practices..........
Parent - By 803056 (*****) Date 04-30-2007 02:09
Make sure you are standing clear when they tension the hoisting cables.

Good luck - Al
Parent - By downhandonly (***) Date 04-30-2007 03:15
It sounds like your boss is a total moron. I'd be looking for another place to work.
Parent - By billvanderhoof (****) Date 04-30-2007 06:35
Equalizing the load on more than four lifting points is very difficult, even the fourth one is questionable sometimes.  If you weld the nuts flat to the "thing" the strain will not be axial to the nuts making the situation even worse.  I concur with those who would refuse to do the nut approach.  Nuts is nuts- sorry, sometimes I can't resist.  Can you somehow jack the "thing" up a foot or so and set it on something safe?  Then you could run a couple of slings around it and lift it in relative safety.
Bill
Parent - - By DaveBoyer (*****) Date 04-30-2007 04:36 Edited 04-30-2007 04:41
WHOA! I retract My above suggestion, now that You have told more of the story. I had figured You needed a way to hold a nut in place in an inacessable area. This is definatly a job for lifting eyes, holes drilled and tapped into the plate, or something that will provide a KNOWN degree of strength, an engineered solution if You will. That "THING" is aprox 17,410 #
Parent - - By darren (***) Date 04-30-2007 06:27
    i agree with dave, i thought the same thing about holding a nut in an unaccessible place,
 
   my question is why is your "guy in charge" not on this forum trying to solve the problem. and why are you doing his job. until the workers refuse to do the job of their superiors then nothing will ever change. it is only because we have been taught the "good slave mentality" that we strive so hard to get jobs done at any cost.(good solid tradesman work ethics are abused until the abuser is stopped) hold those that are accountable, accountable; and let them hang themselves with their own rope of ignorance and ego, then their is a vacancy for someone who is capable of making intelligent and safe decisions.

   tell the boss that if there is no engineered lift, then you refuse to take part. if there are any repercussions the go to the authorities immediately.

  as ive stated before, what would you do if it was your child or grandchild in this situation and why won't you give yourself the same consideration.
men and women have died for our rights and it disrespects their sacrifice when we do not protect those rights.
the usa and canada are not third world countries. the rest of the world is counting on us to be leaders in the realm of safety and workers rights.

  i realize as ive said before it is easy to comment on these things from our chairs , not being immediately tied to the results of your decision, it is your life and your livelihood, however consider this. if you say yes to this what will they expect you and your co-workers to say yes to tomorrow.

   ill get off my soap box now, just remember that there are alot of people counting on good men and women in power to make good decisions so that those good men and women who are not in power can be safe from harm. obviously because you brought this to this forum you know right from wrong, you have the power to say NO, i in my humble opinion suggest you exercise that right before circumstance removes that right, possibly forever
sincerely
darren
Parent - - By JA (**) Date 04-30-2007 08:01
yes , i agree with you all............some of the things people do......????????

and the reason the "guy in charge" won't listen is because he "knows everything"

this is the same guy i saw cutting off the lock to one of his explosive sheds with the cutting torch.............

i don't work for these people , they sub out alot of work to the contractor i work for......we go in and do our own thing.......the "right" way..........and every now and then , stand back and watch the show.......
                                                                                                             and thank all for your input........
Parent - - By jwright650 (*****) Date 04-30-2007 12:25
Run Forrest Run!.....I'd call in sick that day, no way I would want my name associated anywhere near that disaster-in-the-making.
Parent - - By 803056 (*****) Date 04-30-2007 12:56
JW; I love your quote, "Run Forest, run!"

We all attempt to reply to inquiries in a meaningful way. However, given the limited information we are provided, are we providing a service or a disservice when we respond?

I believe most of us envisioned a typical bolted connection or the need to caputre a nut to prevent it from rotating while being tightened. It was only after several responses were provided that we learned that the purposes of the welded nut was to lift a "heavy" load.

Talk about "mud on your face"! If only there was a way to remove some of my earlier responses to this post!

Best regards - Al
Parent - By hogan (****) Date 04-30-2007 15:48
if you have to do it this way i would suggest that a mag particle test be performed after welding. it won't tell you how the mechanical properties have changed, only if there is crack in the weld or nut.
Parent - - By bellaru (*) Date 05-01-2007 02:33
Al , i'll listen to anything you have to say,,,,,,,,,,,,,sometimes i think they should change the name of this forum to ....."Just ask Al"....

your in there JW,,,,,,,,,,and so are you Henry,,,,,,,,,,oh ya , lets not forget Giovanni...........lawrence is pretty damm good , and sourdough gets us dirty,,,,,,,,i myself am just as dirty.........
Parent - By 803056 (*****) Date 05-01-2007 14:35
The forum is only as good as the folks that ask questions and the free flow of ideas expressed in the answers from the folks that take the time to respond.

We're all novices in some respects. We can not possibly know everything about anything, if you know what I mean. Everyone can be in the process of learning more every day if we just open our minds to new ideas.

I look forward to reading the responses to the questions asked because I get new ideas and a fresh view on "old" problems that seem to reoccur regularly. It is amazing how many times the same (or similar) question is asked over a six month period. That is a good indication that new readers are using this forum as a resource. That's an indication that the "forum" is a worthwhile endeavor. It is the concerted effort of everyone that responds to the questions that strengthens the value of this forum.

I may not always agree with some of the responses and I know right away when someone disagrees with my opinions, but that's the value of this forum. It forces me to rethink the problem and look at it from a different vantage point. It is a sanity check that I find useful.

The one element that I find amazing is the number of questions and responses we get from "overseas". Call it "worldwide appeal" if you like, but I find it valuable to hear from our friends from Brazil, New Caledonia, Columbia, and Germany to mention a few. I enjoy the opportunity to help someone that isn't familiar with our welding standards and I'm always impressed by their willingness to struggle with our "American" english language. I have a hard enough time stringing together a reasonable sentence in English, never mind read and speak a different language. I was asked to "give up" trying to learn Spanish in high school. My Spanish teacher would roll on the floor laughing if she heard I teach courses in Venezuela. Thank God for my great interpreters.

I can't recount how many valuable replies we get from Lawrence, Henry, Chuck, Aevald, and so many others.

I especially enjoy the questions and answers provided by practicing welders. I burned rod for many years (about 20 plus years) before getting into the inspection and consulting end of the business. I appreciate the practical answers we receive from welders as well as the theoretical explanations from Stephen and Giovanni.

We appreciate the compliments, but it is all of us, together, that make this forum such a valuable tool to everyone.

Best regards - Al
Parent - - By jwright650 (*****) Date 05-01-2007 14:53
Well, has this task been attempted yet? I was just scheduling my vacation and I wanted to make sure that I'm out of the way....LOL

Seriously, if these nuts are being welded on to become lifting lugs...just how much weld can you physically get around the perimeter of the nut? If you think about the amount of weld required to lift the weight, you may find with simple calcs that there just isn't enough surface area to get enough weld to lift the thing....regardless of whether the nut has been degraded or not.
Parent - - By ssbn727 (*****) Date 05-02-2007 05:16 Edited 05-02-2007 05:36
I apologize for not staying on topic but I could'nt resist the exchange of acknowledgments being given to our fellow participants who contribute so much to making this forum what it is today - Simply the best!!!
I echo the acknowledgments of the previously mentioned individuals and express my gratitude for their contributions!!! It is here where I feel most "Weldcome!!!"

Let us not forget the "quick Wit" consistent with John Wright!!! Also his willingness to go the extra mile to help a fella out!!! ;) Then there are the interesting comments & guidance from jon20013!!! It's refreshing to see Joe Kane contribute also... Js55 & CWI555 most definitely are a "Weldcome" addition to our contributors as is New Tito (Congrats!!!) What can I say about Stephan??? So much that it would exceed the capabilities of the server(s) for BBS Grand Central ;) Just kidding Stephan!!! ;)

Which Al are you talking (803056 or Aevald) about??? I think they're both excellent contributors as is anyone who participates here because, when we combine our experiences and knowledge (Well, not so much mine but, everyone elses;) ) there's a good possibility & probability that we'll guide you in the direction necessary to aid one in resolving most welding related issues. At the very least we'll learn something from one another!!!

Pipe welder1999 (Gerald), Bill Vanderhoof, SWnorris (For not only his technical expertise but also for his ROTFLMAO comments!!!), Chuck, Tim Gary, Chall, Chet Guilford (For setting the example!!!), G Roberts, Neikke and Professor Giavonni Crisi have helped me out tremendously and that's why I need to recognize them also and it would be almost criminal for me not to mention Shane Feder from the other side of this world of ours - literally speaking of course!!!;) Then there's MBSims, MBlaha, RodofGod and others that I hope will be able to forgive me in being so absent minded by not mentioning them also!!!

Finally the women who also participate here also need to be recognized also with Rebekah as my personal favorite because her worldly travels and her refreshingly inquisitive nature!!! I also enjoy the contributions from Christine that have helped make this forum even better than when I first stumbled upon it a few years ago ;) I cannot forget to mention the newcomers & students that are refreshingly young in their careers who keep us oldtimers sharp with excellent questions ;)... All of the Educators because they have given me some interesting ideas to work with over the years!!!

To sum it up in a nutshell... All of you have contributed in resurrecting my welding career during my darkest days when I was an irritable SOB, looking for a place to reach out and to once again find the commraderie that was missing in my life a just a few years ago...  I guess from going through the life changing event that left me very isolated and fearful with respect to the uncertainty of my career during that time, and as if to add insult to injury - the mental anguish I experienced going through my hip surgery a few years ago turned me into someone I knew needed to change his ways or give up on getting his career back on track!!! Lord only knows how much I hate quitting or giving up on something thats a challenge on any level!!!

You folks helped me by being there to listen, to critique, to offer some guidance and the opportunity to be of some assistance so that I could emerge once again with enough confidence to get my career back in gear and become a person with a positive attitude again!!! For that - I'm eternally greatful for your help in not letting me quit in my effort!!! ;)

You folks accepted me back inspite of myself and for that I will always be forever greatful so get ready for my TENTH anniversary (Liver Transplant 10/08/97) in October!!!  It will also be the debut of my first sculpture since 1993 which was too long ago!!!

I most definitely concurr with your post Al (803056) in giving the acknowledgment due to everyone that contributes by participating here in this forum!!! Hear Here!!! ;) ;) ;)

Respectfully,
Henry
Parent - - By DaveBoyer (*****) Date 05-03-2007 05:15
Henery, Where is that degaulsing coil? The only one I have ever seen is near Brunswick,  Georgia right allong the Intercostal Waterway. I came up on it in dense fog and thought it was an old iron bridge. I thought I was "Loster than Hell". When I got really close I figured out what it was and did manage to navigate arround it.
Parent - - By ssbn727 (*****) Date 05-03-2007 17:58
Hey Dave!

Kings Bay, Georgia is where you're referring to Sir! If you're ever in St. Mary's, GA nearby - stop by "Ken's Tattoo Shop" and ask for Ken... Retired MCPO who knows those Submarines better than most and creates on hell of a Tattoo if anyone's interested but, do'nt ask too many questions if you catch my drift because if he get's suspicious of you, I cannot tell you what will happen afterwards!!! However, one clue will be his piercing stare into the distance away from your face!!! That's a definite sign for you to "exit stage left!!!"

There is also one up in the Great NorthWest State of Washington... If I remember correctly somewhere near Bangor.

Respectfully,
Henry
Parent - - By Bob Garner (***) Date 05-03-2007 20:25
Henry,

I worked up at the sub base up in Bangor Washington for a while.  Never got to see the degausing facility, though.

We're designing a degausing facility here in San Diego.  The job hasn't really started yet so I don't know what it will look like.  Our biggest problem now is how to align the dang thing; magnetic declination changes over time so for what year do we design for.

Love to hear any comments you have on these facilities.

Bob Garner
Parent - - By ssbn727 (*****) Date 05-03-2007 21:34
Hey Bob!

No Disrespect there but, you should know better than for me to even attempt describing the details of this type of facility either in a public forum or in a private message!!!

For reasons of operational security:
That's a BIG HELL NO!!! Sorry CHARLIE!!!

The only way you're going to get that info is by going through the appropriate channels, and you should know that if you worked at the Submarine Base especially knowing the type of security that's there!!!

If you've got the required connections with the USN and have passed ALL of the security checks, then they'll be more than happy to assist but please, do'nt even think of communicating about that type of stuff online and/or on an unsecured network for crying out loud!!!
REMEMBER WE'RE STILL AT WAR!!!

                  "LOOSE LIPS SINK SHIPS!!!"

Henry
Parent - By swsweld (****) Date 05-04-2007 06:18
I didn't read every sentence to every post so I my be repeating a previous reply but if the plate is four inches thick it needs to be pre and post weld heat treated. I know a previous suggestion was to Mag particle test the welds to check for cracks. It doesn't sound like the guy in charge is going to buy into "doing it the right way" since he rejected lifting lugs in liew of welding nuts. As a mininum preheat should be done.

I know preheat was mentioned early in the thread but I think that was before the weight and thickness were mentioned.
Hope all goes well.
Parent - By Bob Garner (***) Date 05-04-2007 19:38
Whoops!

Had no intention of seeking info on these facilities, just trying to make conversation.  Yes, I have all the Navy clearances and certainly didn't intend to ask something out of bounds.  I just dig working on state of the art stuff.

So, in lieu of discussing that, Have a great weekend everybody.

Bob Garner.
Parent - - By Stephan (***) Date 05-05-2007 10:39
Hey Henry!

Just "stumbled" on this fantastic thread! And you and all the other appreciated fellows may forgive me for not dealing with its origin, but...

I don't know how to say it in English, in Germany we would say: "Waaaaaaaaaahnsinn!" (WOOOOOOOOOOOOOOW in English?)

I must repeat myself - You are really  g r e a t !

Not only in regard to your extraordinary intellectual knowledge but also - as I can see - in physical ;-) .

I love the forum!

Best regards,
Stephan
Parent - By ssbn727 (*****) Date 05-05-2007 19:35
Hey Stephan!

Your words are too kind!!!
If you only knew how much I really do'nt know about stuff as you think I do, you would'nt hold me in such high esteem IMHO. About the only thing that I'm sure I know is that there is so much that I need to learn, and so little time in life to learn what I need to know so that I could put it to good use!!! Hence the addage: "Life's too Short!!!"

I do enjoy reading the your posts that show your own efforts to immerse oneself in getting to understand what's really going on with respect to the "inner workings" of welding arc physics & mechanics, your understanding the chemistry & physics, and how they interelate to comprehending the metallurgy that's involved with each & every weld along with the mechanical/physical changes going on not only inside the weld but outside or adjacent to the weld as well.

Your overall passion in explaining to the rest of us what you have learned from others that have shared their knowledge and experience with you shows - at least to me your willingness to share your knowledge freely and without conditions!

That to me is noble and worthy of recognition!!! To think that some of us were at first hesitant in acknowledging that now indisputable fact - speaks volumes of your persistance in sharing your knowledge and being a part of the forum!!! For that alone, I'm greatful for you to be a part of this community ;)

Respectfully,
Henry
Parent - By aevald (*****) Date 05-04-2007 22:24
Hello Bob, your comment on Bangor got me to thinking of a bit of time I spent there. Wasn't in a welding capacity though, I was actually replacing a roof on a structure there. At the time, they had just blown up the embassy in South Africa so security was much tighter than it had been up to that point(not anything like I would imagine it is today). Oddly enough it was deer hunting season and they were letting the public in to bow hunt on the base. Seemed like somewhat of an odd contrast. Having heavily guarded entrances and checkpoints and then seeing hunters running around in camouflage greens carrying bows. Couldn't resist the little sidelight here. Regards, Allan
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