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Us of Bolt Tension for Nuts Loosening

04/06/2011 6:06 AM

Hi all;

When loosening nuts we have used hydro torque, the problem was that we 've damaged many of the studbolts and got difficulties to carry out the job.

I start thinking to use bolt tension to loose nuts?

please can you advice

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Anonymous Poster #1
#1

Re: Us of Bolt tension for nuts loosening

04/06/2011 6:54 AM

Your mail/problem is not very clear.

How were the studs initially tightened?

What was the exact reason of the damage? There is a possibility of the nut getting jammed in the threads due to galling/other cold weld mechanism or even simple rust.

Anyway in case the joints (ie the fasteners) are stressed to their limits it is usually advisable to replace the studs once you loosen them. Tensioning the studs to release the nuts can only be done to a limit based on the initial preload and the bolt properties.

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#3
In reply to #1

Re: Us of Bolt tension for nuts loosening

04/06/2011 9:09 AM

Hi;

Thanks a lot for the comment.

I am not specialist in bolting so I can not answer what was the reason but it seems some colt weld and in my point of view these were tensioned during phase construction and need to be loosen by tensioning !!!

Actually; it was the first time (triennal Shutdown for Inspection) since the plant was handed over by construction. Of course we replaced automatically all the bolts. Now we will shutdown the 2nd train and we will use bolt tensionning to tight some of the flanges depending of bolts size, pressure rate, service condition...

My question was is it possible to use bolt tension to loose bolts?

Thanks for all

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#2

Re: Us of Bolt Tension for Nuts Loosening

04/06/2011 8:43 AM

it sounds like they were over torqued to begin with. they do make a tool for measuring this. i have seen them used for connecting rod bolts. it measures how much it streched.

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#4
In reply to #2

Re: Us of Bolt Tension for Nuts Loosening

04/06/2011 9:26 AM

Hi Darren2264

It makes sense, sub contractors use such tricks as long as it will not leak during leak test.

Thanks a lot Darren2264

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#5

Re: Us of Bolt Tension for Nuts Loosening

04/06/2011 11:50 AM

Try using a torque wrench.

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#6
In reply to #5

Re: Us of Bolt Tension for Nuts Loosening

04/06/2011 3:56 PM

Thanks KJK

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#7

Re: Us of Bolt Tension for Nuts Loosening

04/06/2011 11:42 PM

I don't know what you mean by using bolt tension to loose nuts. Google does not seem to help. What did you mean by that statement?

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#8
In reply to #7

Re: Us of Bolt Tension for Nuts Loosening

04/07/2011 2:05 AM

Hi Jusef

I think he means tweaking, nudging the bolt clockwise before undoing it. He is a bit unclear but I have done that with very tight bolts or even rusted ones. If you can get it just a fraction tighter, usually followed by an audible crack sound, then undoing is easy, that's how I understand it.

Lets see what comes out of this, Ky.

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#11
In reply to #7

Re: Us of Bolt Tension for Nuts Loosening

04/07/2011 6:44 AM

The OP meant (I assume)

The fasteners were originally tensioned. Now the nuts are jammed. So whether he sould use a stud tensioner to stretch the bolt (that will of course loosen the frictional grip between the nut and the surface of the component). Then slightly withdraw the nut and then if he removes tensioner the loosened nut can be easily removed.

This method is theoritically OK provided

a) He means to replace the fasteners.

b) Takes suitable precautions for the fastener breakage during the tensioning. Since the fasteners were initially tightened to the designed value the slight overtightening for removal may not actually break (though may) but is likely to cross the yield point (hence (a) above). However in case of improper tightening (I have seen people using hammer drive wrenches (forged spanners) in case of leakeges ) fingers are crossed even for breakages in tensioning.

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#12
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Re: Us of Bolt Tension for Nuts Loosening

04/07/2011 7:11 AM

I had no idea either.

From http://www.htico.com/variable-stud-tensioners.html

How The Variable Model Stud Tensioner Works

The operator selects the Puller Bar, Bridge and Nut Rotating Socket for the stud and nut size to be tensioned. After placing the Bridge and Load Cell Housing over the nut, the operator threads the Puller Bar onto the stud. He then connects the Stud Tensioner to the Hydraulic Pump, using Hydraulic Hoses with Quick-Disconnect (QD) fittings. The Hydraulic Pump supplies high-pressure hydraulic oil to the Tensioner Load Cell, producing an accurate axial tension that stretches the stud. When the pump reaches a pre-set pressure, the operator uses a small bar to tighten the nut by hand. He then removes the Stud Tensioner and the process is completed.

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#13
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Re: Us of Bolt Tension for Nuts Loosening

04/07/2011 12:23 PM

Ahhh...well there you go then!!! I wonder why google didn't find that info for ME! So yes, I can see how the problem might arise...if the studs cannot stretch (like if the threading in the work piece starts right at the top!) then this tensioner would break as many studs as it fixes! But, on a long bolt with considerable non-threaded portion, this machine would work a treat!

Hats off to discovering a new tool at MY age! Well, the day can only go downhill from here!

I would try pretty much any other means of getting this nut off before I would put this machine on. If the nuts cannot be loosened by any other means, this might do it. But yes sir, I think you will break a couple of studs in the process. Then of course, your problems have just begun! Broken studs are not as bad as broken taps, but honestly, they run a close second! Then you have to drill them out. NOT a happy time!

I imagine you could use a lot of other methods to tension a stud and still allow access with a wrench.

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#9

Re: Us of Bolt Tension for Nuts Loosening

04/07/2011 5:27 AM

I don't know anything about this sort of thing, but, would going around with WD40 or other releasing fluid an hour or so before undoing the nuts help?

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#10

Re: Us of Bolt Tension for Nuts Loosening

04/07/2011 6:35 AM

bolts can easily be broken by being undone by enormous forces = damaged studs.

This could be caused by thread seizure by corrosion or thread sealant.

Often heat cycling with a torch or penetrating oil or cryo shrinkage will help.

When nuts are applied, the proper tension is needed and the proper thread lubricant and locking method

http://www.hytorctexas.com/

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#14

Re: Us of Bolt Tension for Nuts Loosening

04/13/2011 3:47 PM

Yaqoub,

You can only use bolt tensioners to loosen the fasteners if there is sufficient thread length beyond the nut. Usually, this requires a length equivalent to one nominal thread diameter.

Another thing to note is that if the studs are damaged (yet they are long enough), it could be very difficult to remove the nuts since you'll be using minimal force to turn the nut via the nut-rotating socket and tommy bar.

I think that you need to consider the root-cause of your problem: "Torquing" is a destructive bolt tightening method (as well as being very inaccurate). Not only does it require the nut to be dragged radially across the spotface (with the potential for significant galling), one usually has no idea if the threads of the studs are being ripped apart due to a bit of dirt, rust, scale etc when the nuts are being forced down the stud.

You're correct in that tensioning would be easier. Since this method doesn't rely on forcibly driving down a nut, the damaging effects of torquing that you're now experiencing will be avoided. Thus, on critical applications (especially larger sizes) specify longer threads so that you can tension both at tightening and at releasing.

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#17
In reply to #14

Re: Us of Bolt Tension for Nuts Loosening

04/14/2011 12:09 PM

I always get some resistance when I point out that the only way you can get accurate torque is to make sure it is "wet" torque. That is, to lubricate the threads. Dry torque is downright hazardous. And yet I have people suggest that if you oil the threads before applying the torque wrench you will somehow sow the seeds of destruction down the line as the nut backs itself off.

When we do this, our torque values are pretty close, clearly close enough for most applications. It has been the approved method for decades, perhaps even centuries.

Your company of course makes a living out of scaring people into buying your equipment. (wheels come off..cranes fall...that is from your web site.) Normally I find such tactics to be reprehensible, (An example of this tactic would be..."I don't know sir, but I would not drive another mile in that car...now THIS one will get you and your loving family home safely!") but in the modern day and age of CEO's that don't have a clue what is being manufactured on the factory floor, a little emotional motivation may well be a good thing.

That being said, I suspect that hydraulic tensioning may well become the standard in the future. There is no doubt that it is a better way than just torquing nuts and bolts, particularly in a factory setting.

I am looking forward to seeing the technology in my local garage in the near future. Do you think it can be scaled down to local levels? Is there any reason there can't be a hand pumped system?

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#18
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Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 4:30 AM

Yusef1,

There are many options available to tighten fasteners. These include:

  • beating & bashing
  • heating
  • hand torquing
  • "enhanced" hand torquing (ie - use of cheater bars)
  • impact wrenching
  • powered torquing (pneumatic, hydraulic)
  • tensioning (mechanical or hydraulic)

In all of the above nut-turning methods, it must be remembered that one CAN'T know how tight a fastener is just by knowing how much force was applied during the tightening process!!! To say this would be like saying that you know how hot a vat of boiling oil is because you know how many logs were thrown into the fire. Ludicrous, right? You'd have to stick a thermometer into the vat in order to be able to say how hot it is. Same thing goes for bolting: You have to measure how tight the fastener is AFTER it has been tightened!

Each tightening method has its merits and disadvantages (some much more serious than others). The choice over which method should be used depends upon the nature of the application. Central to such a decision would be a risk analysis determining the cost of failure. In some cases it's sufficient to simply use a flogging spanner over the nut and whack it with a big hammer. In others you may have to go to the other end of the scale and tension followed by load verification.

Whereas you likely won't see bolt tensioners being used in your local garage in the near future, run down to your local large diesel shop (ie at a rail yard or ship yard) and you'll see plenty of applications, particularly on European-based OEM engines. You'll also see them being used in power plants, refineries, steel mills, bridge construction, pipelines, subsea flanges, mining and many other areas. It's not a new technology; it's been around for quite some time

Happy (and safe) bolting!

* by the way, yes, high pressure hydraulic hand pumps are indeed available for use with bolt tensioners.

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#19
In reply to #18

Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 9:08 AM

Re: In all of the above nut-turning methods, it must be remembered that one CAN'T know how tight a fastener is just by knowing how much force was applied during the tightening process!!!

Well, I understand that you *can't* tell how tight a fastener is by the torque applied. But when you know the tension applied (as in hydraulic tensioning) and then use a nut to essentially maintain that tension (instead of trying to increase the tension by more torque--i.e., sort of a snugging down of the nut (sufficient to overcome things like the spring force in lockwashers)), I would think you're pretty close to knowing the tightness of the fastener. (Meaning the force holding the two halves of whatever you're bolting together.)

Sorry for the run-on sentence. ;-)

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#21
In reply to #19

Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 10:56 AM

Close, rhkramer, but alas, no cigar

While it is recognized that act of tensioning bolts is much more accurate (and easier on the fasteners) then torquing them, Tensioning is not completely without concern about final load...

When using bolt tensioners, one has to contend with thread relaxation once the hydraulic load has been released. This is why the applied tension is always somewhat higher than residual tension. Hence, to be completely sure, measure what you have and then, "tune" the load by applying more (or sometimes, less) pressure.

If one performs anything less than "100% Tensioning" (meaning that each bolt is tensioned simultaneously), load transfer (sometimes referred to as "cross talk") comes into the picture. This is another reason why on the most critical applications, full QA should include final load verification.

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#22
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Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 11:00 AM

I don't smoke anyway. ;-)

But thanks for the explanation.

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#20
In reply to #18

Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 9:47 AM

D@mn. And here I was using torque wrenches to rebuild engines and tighten screws and bolts on airplanes for nigh on 40 years, only to discover that it doesn't work.

I doubt that very much.

I will continue to use my torque wrench, and demand my mechanics use theirs in a conscientious fashion. And we will see if we can justify the expense of a fancy tensioning system. The old standby seems to have been fine so far...in that I have not blown a gasket on any of the engines I have ever re-built. My mileage seems to differ...

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#23
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Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 11:14 AM

Yusef1,

It "doesn't work" only if you've had failures. If you've never had leaks, if a joint has never come loose in service, if a wheel nut has never backed off, if you've never stripped a thread, of course what you've been doing works! Remember, the method chosen to tighten a fastener and whatever degree of QA is required depends completely on the cost of potential failure.

If somebody's mechanic's conscientious fashion provides them with enough faith in the reliability of a critical fastening system (for example, the wheel nuts on a car being driven out of a garage by a mother with three kids in the back seat) then all is fine. Let me emphasize that I'm not being overly dramatic here: I almost once became a road pizza because a wheel had let loose off of a transport truck roaring down the highway. This projectile came crashing into my car at a relative speed of over 150 kmh! Luckily, I had swerved at the last minute so that only the complete side of the car was demolished rather than the cockpit (with me in it). The "new" wheel nuts and studs on the trailer had failed even though the "proper torque" was applied

One can't argue against it: "torquing" is guessing. The saving grace is that in many applications, guessing is good enough.

A final note: Please don't misunderstand that I'm suggesting that all joints should be tensioned. That would be silly! For one thing, tensioners wouldn't be practical for quite a few joints and would be vast overkill on others. Torquing or even whacking a nut with a big hammer is often fine... even on critical applications! However, when the applications are critical, do everything that you can to eliminate the guess work and thus reduce the risk to either property or lives.

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#26
In reply to #23

Re: Us of Bolt Tension for Nuts Loosening

04/18/2011 11:20 AM

You see...the problem is...the people that participate in this forum are engineers. This means that if they agree with your statement that "all torque wrench values are incorrect and will result in failure" means that every signature they put on paper for the last 40 years may come back to bite them. So its not a matter of being over-dramatic....its a matter of reality.

I think most people feel that pre-loading a bolt or a nut with a torque wrench is a pretty valid method to ensure the correct pre-loading is in place. Its been used successfully for decades, if not centuries. I have not been able to find any support to your ad companies stated claims that there is as much as 50% variation in tension between properly torqued bolts. I simply don't believe it. But then, we don't live in a perfect world. **** happens! I have found several studies which note that there can be as much as 5% variation, most of which can be shown to be because of shared loads...like when you tighten any flange nut, all the others loosen a bit, and these studies explored ways to minimize that effect.

Wheels come off because of improper torque techniques...or human element failures (forgot to more than finger tighten them! Doooh!) or unforseen factors such as grit in the threads, or improper anti-seizing compound being applied. Not because the torque wrench method is fallible.

That being said....I can see every engineer in the world looking at this thread thinking to herself..."gee...if they want my signature, they better tension those bolts". (bet that would make your marketing department happy!) I really DO think that tensioning is a superior way to "torque" screws, bolts and nuts. So maybe we really SHOULD look at this technology, and see if we should put a tensioner into every bicycle shop, and general mechanic's garage in the world, and allow the torque wrenches to simply gather dust.

I don't know guys...what do you think? Its not such a silly idea. Now that you know the problems of torque wrenches, will you ever again sign off on a job that was only assembled with torque wrenches? That would include all aircraft, bicycles, bridges and pretty much anything else that isn't riveted together!

I know...I am gradually sliding off topic!!!! Perhaps I should simply start a new thread. Torqued thread of course...grin!

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#27
In reply to #26

Re: Us of Bolt Tension for Nuts Loosening

04/18/2011 12:05 PM

Yusef1,

Although a bit of cynicism is healthy, you completely miss the point! Nobody is saying that all joints should be tensioned rather then torqued! Once again, the point is...

Any method used to tighten bolts can result in preloads inconsistent with what is expected. Torque-tightening just happens to be the method which can be the most inaccurate. Furthermore, it can cause the most serious problems because it creates a dangerous false sense of security in those who don't fully understand the mechanics. Yousef, you don't need to read a report to understand that torque-tightening can be out by not just 5% or 15% or 50% (it can even be out up to 100% !). Let me try to make this clear to you and to anybody else who doesn't quite understand this yet:

Consider a bolt being threaded into a blind hole. Once it can no longer by turned by hand, additional torque is applied by a calibrated torque wrench. This torque increases until the specified value has been achieved. If the bolt is part of a group of fasteners in a flange, the others are tightened in a prescribed sequence with the former likely having the specified torque being applied at least once or twice again. Now, are you sure that the bolt is tight? You'll be willing to sign-off on it because you've witnessed not only the installation but also the calibration process of the wrench and, you were there to witness the 'proper' application of lubrication, right? Hmm... I wouldn't want to be in your shoes because, what had actually happened was that the bolt had seized in the hole due to thread pick-up. This meant that even though the "proper" torque was applied with a calibrated torque wrench under "proper" conditions, the clamped constituents are still loose!! The bolt and its close neighbors will likely fail in fatigue. Surely you can see this now? Need another example? How about this:

Four bolts are being used to secure the "dead-nuts square" bedplate of pump. They're all torqued to the same value in a well-defined pattern. Upon start-up, high vibrations are noticed. After looking at the possible issues, the actual cause has been determined to be from "soft-foot". But how can that be, especially after you verify each bolt's torque again with your calibrated torque wrench. I'll tell you how: One of the bolt holes had crud in the bottom of it. As a result, the bolt bottomed out before it could fully clamp the base of the pump. Hence movement at that corner! Nevertheless, since you used the "proper" equipment and you followed the "proper" procedures, you made the call that it was tightened properly

Here's another key point that we all need to accept:

  • "Torque" is not an indication of how tight a fastener is. "Torque" is only a measurement of the degree of resistance felt when trying to turn either a nut or a bolt head.

There's nothing wrong with being wrong. The problem (and danger) arises when one can't admit it.

Happy bolting, everybody!

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#28
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Re: Us of Bolt Tension for Nuts Loosening

04/18/2011 12:39 PM

Ooops, sorry Yusef1, I see that you did aknowledge the point. As a result of encountering so many Luddites who because of doing things the same way for ages simply can't understand the clear logic of the argument, only a certain part of your message registered in my feeble mind I can clearly see that you sir, are indeed an open-minded engineer!

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#29
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Re: Us of Bolt Tension for Nuts Loosening

04/18/2011 5:24 PM

Good on Ya.

This was turning into a very tight thread and then all this tight talk. I better go and check my engine mounts today, haven't done that in years .

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#30
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Re: Us of Bolt Tension for Nuts Loosening

04/19/2011 12:30 AM

Blind holes! The bane of a mechanic's existence. I wonder how one would tension a bolt into a blind hole.........

What does a conscientious engineer do when he or she finds out that something was done wrong? Don't you go back and demand that it be done right?

Why has this NOT happened in garages and bike shops and aircraft hangars across the land by now?

I don't think it is because we are all luddites who cannot embrace new technology! I mean, we are all reading this on a computer! Problems of bad torque values are many and pretty much universally acknowledged. Blind holes, rusty threads, flattened lands, poor lube, excessively long shoulders, switched out metric bolts on SAE nuts...all exist and have often resulted in serious, sometimes drastic problems. I myself drove a car out of the garage, only to find the mechanic had only finger tightened the wheel nuts!

I think the reason why there is not a big rush to go back and check all my work over the last thirty years is that I trust the torque values I set on the day to deliver the correct pre-load to the fasteners I was responsible for. My signature is still there, flying along with a lot of airplanes! The idea that there might be a better way to tension a bolt doesn't cause me to lose much sleep because I know I did it right the first time.

The vaunted "feel" of the mechanic occurs when the mechanic can tell "something is wrong", and I even remember when Al Bourque, my supervising master corporal discovered that the screw supplied to him was insufficiently threaded, the shoulder was too long, and was chewing into the female threads. You had to look sharpish at it, it was only one thread, but it would have thrown the torque off for sure. And that was for a generator mount, which if it had come loose, might have created some serious fod damage, assuming the generator didn't come off the engine!( Mind you, they were all wired on as well, we don't let those ultra critical bolts get too loose!)

So we in the aircraft industry take our fastenings very seriously. Until you see a mechanic tightening up the thousands of screws in the bottom of the wing with a torque wrench, you almost cannot credit our obsessive attitude. (click, next. click, next. click next)

But problems with torque values are old news, and many methods have been devised to over come these problems. And we really HAVE over come them. Or I would never fly in a plane I fixed! But everybody admits that it is a constant battle. The remarkable thing about tensioning is that it neatly sidesteps all the problems related to torque measured tension. Whether we argue about percentages or not, (Your mileage may differ) it is clear that hydraulic tensioning simply doesn't care about all the majority of the problems which might result in a bad pre load. So I am quite excited about it. It will never replace the torque wrench for some applications, but for some others, it may prove to be vital.

So I think I'm a gonna get one of these things for my machine shop.

Mostly because I am mistrustful of these new untried yobos who masquerade as mechanics my HR department seems to be finding!

And now, I have completely moved off topic. So please feel free to mark me down...grin!

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#31
In reply to #30

Re: Us of Bolt Tension for Nuts Loosening

04/19/2011 3:38 AM

Yousef1,

I'm thoroughly enjoying this post and, I think that many readers will likely benefit from it!

Let me throw something else into this: wholesale replacement of torque wrenches with tensioners is neither practical nor even possible. There will always be applications where "torquing" is the most suitable. If those 'suitable' applications aren't critical, the time-honoured methods of torquing are likely completely acceptable even though the load scatter may be quite wide. But what about critical applications where even a 5% load scatter may spell doom but where tensioners can't be used?

Answer: Keep your torque wrenches and torque away! However, in cases like this you need to take an additional step: you need to verify the effects of the torquing exercise so that you can "tune" the applied torque in order to achieve the necessary preload. If you remember the earlier analogy that I had used, this is just like sticking a thermometer into a vat of hot oil so that rather than guessing how hot it might be by counting the number of logs thrown into the fire underneath the cauldron, you're able to get a definitive indication of temperature. So how does this apply to bolting?...

Answer: Measure the relative fastener elongation between a no-load condition and the tightened condition. Elongation, unlike applied torque, is a true indicator of a fastener's load (unless the fastener had at one time been tightened to beyond its yield point). Therefore, if the elongation is too low, apply more torque (or whack the wrench with a bigger hammer, or hang another mechanic off of the end of the cheater bar, etc) until the elongation is such that it is within the acceptable tolerance band.

It usually takes the uninitiated awhile to understand and appreciate this concept. I remember a case years ago at a Power Plant where there were issues with closing the low pressure casing of a large steam turbine (the flange was warped). I was brought to site to measure the elongation of the bolts as they were torqued. When the specified value was applied, there was hardly any elongation evident. I then instructed the millwright to apply more torque. Being a very concientious sort of fellow, he balked at doing so because he felt that he was going to yield the bolt. It took quite a bit of persuasion and explanation to get him to accept that he could in fact keep applying torque even though his "tables" suggested that he would be tightening to beyond yield. Such over-tightening wasn't going to happen because even though he applied maximum torque, he was nowhere close to yield! (in serious cases like this, the thing to be concerned about is torsional stresses). Eventually, the necessary elongation was achieved and the joint was closed (at substantially higher torque values than specified).

Elongation measurement is relatively easy. One can do it with simple verniers or dial indicators. In heavy industry we use specialised ultrasonic technology which fires a burst of ultrasound down the length of a fastener and measures the time that the burst takes to return to the transducer after bouncing back from the bottom. This is done on each fastener in its relaxed state with the values being recorded. As load is applied to a fastener, it's length will increase. After the initial tightening phase (load applied by torque, tension, heat or a big hammer), the length is measured again. The resultant Delta L provides the indication of actual load. If discrepancies are found, either more load is applied or the fastener is backed-off as necessary. No guesswork, no assuming, no hoping, no consulting the spirits. Just actual data that one can be comfortable signing-off on !

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#32
In reply to #31

Re: Us of Bolt Tension for Nuts Loosening

04/19/2011 3:49 AM

With regards to using ultrasound to measure bolt elongation and for those who might be interested, here's a link to a "virtual" device where one can play with it (drag the probe to the top of the bolt, apply some load and see what happens!)

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#24
In reply to #20

Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 11:28 AM

The trouble is that the vast majority of the applied torque is used up in overcoming friction. Try doing up a nut, then, reduce the torque setting and try to undo it; gradually increase the torque setting until you can. The difference between the two settings is double the force required to stretch the bolt using the mechanical advantage of the ramp. Now: how consistent do you think the coefficient of friction is between different pairs of nuts/bolts with slight differences in linearity of the ramps and under differing environmental (covers a multitude of sins) conditions.

Another way to understand this is to realise that nuts/bolts wouldn't work at all if the above wasn't true: the nut would simply "slide back down the ramp" if the majority of the effort was needed to "slide it up the ramp".

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#25
In reply to #20

Re: Us of Bolt Tension for Nuts Loosening

04/15/2011 4:36 PM

GA

There is always a torque point were the nut bolt/nut combination will fail, shear and there will always be a way to undo a nut.

Not much of a surprise because it works like that for anything, be it in any discipline even Music or politics. With enough torquing you can split a hair.

Give me these and a couple of hours and you will have them returned near new. This discussion is about as practical as talking about what makes marriages break up. Any of the parties can be at fault not always equally.

If things go wrong and if there's a buck in it, anything can be undone. There is no such thing as the un-doable nut. Maybe I should start a thread about un-doable nuts and bolts. Just for the articles not the picks .

A door nail is a different kettle of fish, Ky.

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#15

Re: Us of Bolt Tension for Nuts Loosening

04/14/2011 8:54 AM

Thanks for all for your answers guys, you were all very helpful for me.

Many Thanks

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#16

Re: Us of Bolt Tension for Nuts Loosening

04/14/2011 10:00 AM

Since there appeared to be a "Eureka" moment experienced by many people here who had no idea of Bolt Tensioning technology, here's a link that will provide further information.

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