Torque Specs Site

I wouldn't trust any website unless it was a website that is showing the factory service manual. I'd believe Haynes over some random website.

Have you searched for a PDF of the factory service manual? I can usually find a PDF for most everything I've owned.
 
Originally Posted by TheLawnRanger
Is there a reliable website to find torque specs? I have Haynes service manuals but like to double check.


Theres no such thing as a "reliable" torque specification- it doesn't exist.

The best you can hope for is a company to publish something along the lines of "under these conditions this number is recommended" and that's based on averages and experience because torque has no direct correlation to fastener tension and there are too many variables for any specification to capture.

Even then, that's a conditional guess based on a lot of assumptions that can be right or wrong for your application based on a host of conditions.
 
Originally Posted by ABN_CBT_ENGR
Theres no such thing as a "reliable" torque specification- it doesn't exist.


If you can't trust the factory service manual, you can't trust anybody. I've been torquing fasteners for 40 years per factory service manuals and have never had any issues at all.
 
Originally Posted by ZeeOSix
Originally Posted by ABN_CBT_ENGR
Theres no such thing as a "reliable" torque specification- it doesn't exist.


If you can't trust the factory service manual, you can't trust anybody. I've been torquing fasteners for 40 years per factory service manuals and have never had any issues at all.


Simple, read what I wrote again. ( been one of those OEM's who wrote them specifications for some equipment)

They already know the average person will most likely not have the tools and equipment necessary to do things properly.

They also know theres a point where liability ( both brand and civil) attach ( so legal reviews them too) attaches.

They also know they have to give you something to go by for maintenance etc.

So they do controlled experiments with whatever the standard is applicable and come up with a safe comfortable range and publish it.

Then theres the fine print( expressed or implied) that defines that specification ( certain finishes, clean holes, proper threads, proper flatness etc.) that gives them numerous outs.

I can also show you hundreds of times ( many in court) where OEM 'specifications" were not only flat out wrong but actually caused the damage so an OEM is anything BUT an "infallible authority" on anything. Many of them just print industry standard settings with little to no testing to validate it. Others farm it out and base specifications solely on modeling like FEA or Solid works with no actual lab testing.

To your point, published specifications are generally adequate for all "normal operations" ( whatever that is) and they work. Nobody disputes that.

However context is key- the OP asked about "reliable specifications" in general and that's what I addressed specifically.
 
Originally Posted by ABN_CBT_ENGR
They also know theres a point where liability ( both brand and civil) attach ( so legal reviews them too) attaches.


If someone doesn't own a good torque wrench then they don't care about torque specs. All you need is basic tools and a torque wrench to torque fasteners per a factory service manual. Like I said, if you can't trust a factory service manual then you can't trust anybody on what the torque spec should be.

Torquing fasteners per the service manual isn't rocket science.
 
Originally Posted by ZeeOSix
Originally Posted by ABN_CBT_ENGR
They also know theres a point where liability ( both brand and civil) attach ( so legal reviews them too) attaches.


If someone doesn't own a good torque wrench then they don't care about torque specs. All you need is basic tools and a torque wrench to torque fasteners per a factory service manual. Like I said, if you can't trust a factory service manual then you can't trust anybody on what the torque spec should be.

Torquing fasteners per the service manual isn't rocket science.


I don't disagree with anything you said and in context its totally correct.

However, in reality when actual joint loading/tensioning is critical- torqueing ( in any capacity with any tool whatsoever) is the LEAST accurate method of proper and even fastener tensioning and outlawed in many industries as a result. That's a simple fact of physics and well proven engineering constant.

That's all I was saying.
 
Originally Posted by ABN_CBT_ENGR
However context is key- the OP asked about "reliable specifications" in general and that's what I addressed specifically.


No. The OP asked for reliable websites to find, in your words "published specifications (that) are generally adequate for all "normal operations" ( whatever that is) and they work. Nobody disputes that."

He wants the specifications that people would use in the real world to achieve "adequate results for all normal operations". I.E., lug nut torque that will prevent the wheel from coming loose.


The engineering websites state that using a torque wrench can result in 25-30% +/- errors depending on all the variables. We understand that and accept that the torque process is what it is. We don't have any other practical means to measure fasterner connections in the real world. Measuring bolt stretch is not practical for routine automotive applications. You use the word reality without seeming to have any concept of it.
 
Originally Posted by ABN_CBT_ENGR
Originally Posted by ZeeOSix
Originally Posted by ABN_CBT_ENGR
They also know theres a point where liability ( both brand and civil) attach ( so legal reviews them too) attaches.

If someone doesn't own a good torque wrench then they don't care about torque specs. All you need is basic tools and a torque wrench to torque fasteners per a factory service manual. Like I said, if you can't trust a factory service manual then you can't trust anybody on what the torque spec should be.

Torquing fasteners per the service manual isn't rocket science.

I don't disagree with anything you said and in context its totally correct.

However, in reality when actual joint loading/tensioning is critical- torqueing ( in any capacity with any tool whatsoever) is the LEAST accurate method of proper and even fastener tensioning and outlawed in many industries as a result. That's a simple fact of physics and well proven engineering constant.

That's all I was saying.


Yeah, I know. But don't you think the engineers who have specified torque specs, procedures and requirements in a factory service manual haven't done any research or put any thought into specifying a torque spec? Engineering isn't that hard.

Like I said, I've been torquing thousands of fasteners for over 40 years and have never had any issues following the factory service manual torque specs.
 
Originally Posted by doitmyself
Originally Posted by ABN_CBT_ENGR
However context is key- the OP asked about "reliable specifications" in general and that's what I addressed specifically.


No. The OP asked for reliable websites to find, in your words "published specifications (that) are generally adequate for all "normal operations" ( whatever that is) and they work. Nobody disputes that."

He wants the specifications that people would use in the real world to achieve "adequate results for all normal operations". I.E., lug nut torque that will prevent the wheel from coming loose.


Right and they don't exist- here's more

First- a "fastener torque" is meaningless without knowing both the compressive qualities of the joint layers and the shear and tangent loading.

The fastener is normally ( and it better be) the strongest part of a given joint and torqueing to a fastener "max" can often damage the joint and make it unserviceable.

Also for a given stud- you would have a different 'torque spec" for steel, aluminum, magnesium and for various thickness' too to achieve proper tension.

That is "real world" .

You cannot define an "adequate result" without knowing all parts of the equation- anything less is just another guess.

There is no "one size fits all" specification or application and even then torque is meaningless in terms of fastener tension because there is no direct correlation.

That's just the simple truth of the matter regardless of popularity or acceptance.
 
You are saying that I should not use the published specification in my service manual to torque my lug nuts, correct?
 
Originally Posted by ZeeOSix

Yeah, I know. But don't you think the engineers who have specified torque specs, procedures and requirements in a factory service manual haven't done any research or put any thought into specifying a torque spec? Engineering isn't that hard.

Like I said, I've been torquing thousands of fasteners for over 40 years and have never had any issues following the factory service manual torque specs.


Yes I know beyond any shadow of any doubt whatsoever that in many cases the do not. I have been on both sides of that equation and know both to the molecular level.

How I know is that when I design and spec a machine for a process ( and eventually commission and stamp it) one of the first things I require of a machine vendor is their design engineering and QA/QC program to validate the machine.

Then I read all their testing then I often go to the OEM and certify the facility.

You are correct that it isn't that hard but it IS EXPENSIVE and many companies do it, others do it partially and some companies simply risk it on their matrix knowing the odds are on their side.

The truth of how many OEM specifications are "less than reliable" would shock a lot of people.
 
Originally Posted by doitmyself
You are saying that I should not use the published specification in my service manual to torque my lug nuts, correct?


Incorrect,

I said to not "assume" that the spec that is published is the result of endless diligent laboratory testing that covers every possible application and condition and said specification is somehow elevated to a status that it is an absolute that is "inarguable" and all encompassing for eternity.

A good deal of critical thinking, research and a degree of caveat emptor is strongly advised when using generic published specifications because your application may be different than the criteria the specification is written against.

That's what I am saying.
 
You are saying that it is o.k. to use the published specification in a factory service manual for a particular vehicle, but it may not be correct due to insufficient testing of all varialbles. In my case lug nuts that might be exposed to salt, rust, hot/cold, etc..
 
Last edited:
Originally Posted by doitmyself
You are saying that it is o.k. to use the published specification, but it may not be correct due to insufficient testing for that particular instance, in my case lug nuts.


Exactly, nothing more and nothing less than that
 
Originally Posted by ZeeOSix
Originally Posted by ABN_CBT_ENGR
Theres no such thing as a "reliable" torque specification- it doesn't exist.


If you can't trust the factory service manual, you can't trust anybody. I've been torquing fasteners for 40 years per factory service manuals and have never had any issues at all.


+1 Same here.
 
Originally Posted by doitmyself



The engineering websites state that using a torque wrench can result in 25-30% +/- errors depending on all the variables. We understand that and accept that the torque process is what it is. We don't have any other practical means to measure fasterner connections in the real world. Measuring bolt stretch is not practical for routine automotive applications. You use the word reality without seeming to have any concept of it.


I know reality quite well and here is some of it.( old school)

You need proper tension in the field- go to machinery's handbook and get the thread data and then use the thread turn method.

Go back and see where that accuracy is on the engineering website and no torque wrench required- just quick math and a scribe.

It was practical back when I was a millwright and the "way it was done"

A lot of skills have been lost in industry in general
 
OP, it seems that the original recommendation to find and use the factory service manual and/or owners manual for torque specifications stands. Realize that the OEM has put themselves in a very litigious predicament by not having sufficient data to support their published numbers.
 
Originally Posted by ABN_CBT_ENGR
Originally Posted by doitmyself
You are saying that I should not use the published specification in my service manual to torque my lug nuts, correct?

Incorrect,

I said to not "assume" that the spec that is published is the result of endless diligent laboratory testing that covers every possible application and condition and said specification is somehow elevated to a status that it is an absolute that is "inarguable" and all encompassing for eternity.

A good deal of critical thinking, research and a degree of caveat emptor is strongly advised when using generic published specifications because your application may be different than the criteria the specification is written against.

That's what I am saying.


I wouldn't call factory service manual "generic published specifications". They are specifications developed and used by the vehicle manufacturers and their dealership repair facilities all over the world.

You think they are going to lackadaisicaly print torque requirements and specification to be used all over the world and not think about any legal ramifications of specifying torque specs that could cause any kind of dangerous situation?

If anybody can't trust the factory service manual torque specs, then the only other option they have is to hire an engineering staff and build a testing laboratory to test out the required torque specs of every fastener ever used on any vehicle.
 
Originally Posted by doitmyself
OP, it seems that the original recommendation to find and use the factory service manual and/or owners manual for torque specifications stands. Realize that the OEM has put themselves in a very litigious predicament by not having sufficient data to support their published numbers.


Welcome to Earth

There is no manufacturer on this planet that does anything that doesn't directly contribute to or protect the bottom line at the expense and risk to everything and everyone else.

They will take every short cut possible, weasel word to the point of deliberately misleading and confusing people, sometimes outright lie, deliberately hide information and more. All in the name of profit.

It will be justified by business decision based on a risk matrix vetted by legal and they will play the odds

Unless its a coded application where possible criminal liability attaches for duty of care ( and even then be careful)- take everything published with a degree of legitimate question.

Just look at product liability lawsuits from forensic failure to warranty and see for yourself- its not like its difficult to find.
 
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