Uh Oh!!!

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Hey all. So I was replacing my seal on the coolant flange to the head tonight. The job was going unbelievably smooth until I was torquing the bolts back on. I had a torque wrench set to 7lbs. Hand tightened back and forth evenly to get an even pressure. Then used torque wrench to tighten back and forth. One bolt snugged up and torque wrench clicked. The other never seemed to get to that point then I heard a snap. Looks as if the bolt broke! Not entirely just the threads separated. I will try and post a picture of the bolt , I haven't used the new format yet.

I'm thinking there's a few possibilities. Could be my crappy torque wrench is way off caliber, I did do a test run with a separate bolt in the vice and it did function properly at various settings. I did this knowing its not the best quality and it did trip with little force. I even dialled it down on the troubled bolt and had it trip at about 3 or 4 lbs. Dialed it up to 6 and it snapped the bolt. This could be entirely my bad and now am paying the price for not investing in a new torque wrench , but I definitely don't think I was applying much force, and given the other bolt snugged and tripped the wrench?? Any insight on this? I don't think I cross threaded as I hand tightened with ease right up to the bolt head......

Let me try and post a pic before I ramble on more lol.......
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Hey all. So I was replacing my seal on the coolant flange to the head tonight. The job was going unbelievably smooth until I was torquing the bolts back on. I had a torque wrench set to 7lbs. Hand tightened back and forth evenly to get an even pressure. Then used torque wrench to tighten back and forth. One bolt snugged up and torque wrench clicked. The other never seemed to get to that point then I heard a snap. Looks as if the bolt broke! Not entirely just the threads separated. I will try and post a picture of the bolt , I haven't used the new format yet.

I'm thinking there's a few possibilities. Could be my crappy torque wrench is way off caliber, I did do a test run with a separate bolt in the vice and it did function properly at various settings. I did this knowing its not the best quality and it did trip with little force. I even dialled it down on the troubled bolt and had it trip at about 3 or 4 lbs. Dialed it up to 6 and it snapped the bolt. This could be entirely my bad and now am paying the price for not investing in a new torque wrench , but I definitely don't think I was applying much force, and given the other bolt snugged and tripped the wrench?? Any insight on this? I don't think I cross threaded as I hand tightened with ease right up to the bolt head......

Let me try and post a pic before I ramble on more lol.......
Were the bolts installed dry or lubed?
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
They weren't dry, there was a fair amount of oil / coolant / fluid on them . It was residual however I wiped some excess gunk off before reinstalling . So not lubed but not bone dry!
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Ok I think the pics worked! So Krash you can see maybe on the dryer side ??

Another question does this mean I'm looking at tapping and dying the bolt hole?? Or think it's possible to get a new bolt in? Or am I all out hooped!?? Thanks again krash for all your responses on this!
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Ok I think the pics worked! So Krash you can see maybe on the dryer side ??

Another question does this mean I'm looking at tapping and dying the bolt hole?? Or think it's possible to get a new bolt in? Or am I all out hooped!?? Thanks again krash for all your responses on this!
That does not look like a stretch bolt but it definitely failed in tension...

As a general rule of thumb, you knock 20% off the bolt torque if you lube a bolt up prior to installation. I have to work with these equations daily in my designs, so that's just a general weekend mechanic number, not the realistic engineering value.

So that bolt failing in tension was definitely due to overtorqueing. Whether it was a one time shot (it it was all good and you just broke it tonight) or it had yielded in the past (think stretching) and tonight it reached it's ultimate tensile strength, it's hard to tell.

But the good thing is, it doesn't look like there any remnants of tapped hole threads, which means the hole threads are still likely in good shape.

I would say clean the hole or and take a look with a mirror if you can. Get another bolt. Try and thread it in. Don't use that torque wrench and go by feel... The smaller bolts you just need snug and a bit extra.

Another thing to note here is it you're taking a torque wrench, that reads in ft-lb, to that low of a value, they really become inaccurate. When the torque numbers start getting that small, it's time to switch to a wrench that can do the deed in in-lb. More accurate and you won't blow past your torque value.

One more bit of advise, think of it like this...7 ft-lb is you putting 7 lb of force on the end of a 1 foot handle. Let's say your wrench is a 6" handle. The amount of torque you need on that bolt is the equivalent to balancing a 14 lb dumbbell on the end of that handle... It's not much! But thinking like this can help you gauge low values if you don't have access to the appropriate wrench.

I can say with honestly I probably torque 75% of the bolts on my car. The other 25% usually you can't get into the area with a torque wrench, so just think in terms of the above analogy
 
Last edited:

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
That does not look like a stretch bolt but it definitely failed in tension...

As a general rule of thumb, you knock 20% off the bolt torque if you lube a bolt up prior to installation. I have to work with these equations daily in my designs, so that's just a general weekend mechanic number, not the realistic engineering value.

So that bolt failing in tension was definitely due to overtorqueing. Whether it was a one time shot (it it was all good and you just broke it tonight) or it had yielded in the past (think stretching) and tonight it reached it's ultimate tensile strength, it's hard to tell.

But the good thing is, it doesn't look like there any remnants of tapped hole threads, which means the hole threads are still likely in good shape.

I would say clean the hole or and take a look with a mirror if you can. Get another bolt. Try and thread it in. Don't use that torque wrench and go by feel... The smaller bolts you just need snug and a bit extra.

Another thing to note here is it you're taking a torque wrench, that reads in ft-lb, to that low of a value, they really become inaccurate. When the torque numbers start getting that small, it's time to switch to a wrench that can do the deed in in-lb. More accurate and you won't blow past your torque value.

One more bit of advise, think of it like this...7 ft-lb is you putting 7 lb of force on the end of a 1 foot handle. Let's say your wrench is a 6" handle. The amount of torque you need on that bolt is the equivalent to balancing a 14 lb dumbbell on the end of that handle... It's not much! But thinking like this can help you gauge low values if you don't have access to the appropriate wrench.

I can say with honestly I probably torque 75% of the bolts on my car. The other 25% usually you can't get into the area with a torque wrench, so just think in terms of the above analogy
awesome thanks for this!! My wrench actually is small and in inch pounds, so I had it set to 84 in/lbs. That being said it is a piece of s**t. Sorry for the language, but I bought it fairly low price years ago and took care of it not to bang it and always stored it securely. It works great for my drain plug and truck diff etc but I agree this is too precise for it. I'm kicking myself now for all the times I saw quality one for 50% off and never acted on it. This all being said I am still somewhat sceptical its all on the wrench. I actually backed the bolts off with the torque wrench, my thought being if It trips trying to loosen perhaps they're over torqued or seized from being there for 17 years. They came off no problem, and I noticed they were similar to a drain plug, like they cracked and then were finger loose. Thats why it surprised me one bolt went on like that and one just gradually met resistance.

Anyway after this fiasco I loosened the pressure on the other, hoping not to damage the o ring with uneven pressure. Tomorrow I'll seek another bolt or two from VW. I'll check the hole with a light and mirror , perhaps even use a spacer and the new bolts without the flange on to see if they snug to determine if I potentially have stripped threads. I am in agreeance with you tho, I see no evidence of metal shavings and the bolt backed out perfect so fingers crossed the threads are ok.

And thanks for the visual on the lbs of force! When you put it like that I can see maybe my junk wrench did over torque! Or me lol. I'm thinking ill heed your advice and snug by hand with my small 1/2" drive ratchet . Hey thanks again!
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
I bought a digital torque wrench from Harbor Freight a few years back. Took it back the next day.
Seems to me 7 '# is not enough to snap that bolt. But it looks like you're fine to finish. Bad wrench, damaged bolt, does not matter now.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
I bought a digital torque wrench from Harbor Freight a few years back. Took it back the next day.
Seems to me 7 '# is not enough to snap that bolt. But it looks like you're fine to finish. Bad wrench, damaged bolt, does not matter now.
Ya I’m just gonna do it with my small ratchet by hand. Here’s to hoping I didn’t mess up the threads!

I called VW they had no bolts local but gave me the type and size. So got from Napa and will try and sort this out tonight
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
So Napa didn’t have the correct bolt size in the end. The size VW gave me was M6x22. Napa had M6x 20. I bought some anyway as it was $3. I might check a few more places like hardware stores quick.
Any opinions on weather the slightly shorter ones Napa had would work ? My other thoughts are quickly check auto wreckers tomorrow. Last resort order from VW and wait til the weekend at the earliest. In the meantime does anyone know if there’s a place on my car with the exact bolt I could “ steal “ for the time being and hat least get it back together ? Obviously off something of less importance. As well is this bolt gonna be some sort of specialized material or in some way that I should be avoiding just using one from a hardware store ? Sorry for all the questions! I’m just hoping to deal with this sooner than later as it’s not ideal to leave it in it’s current state in my garage for the next week waiting for parts
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
So Napa didn’t have the correct bolt size in the end. The size VW gave me was M6x22. Napa had M6x 20. I bought some anyway as it was $3. I might check a few more places like hardware stores quick.
Any opinions on weather the slightly shorter ones Napa had would work ? My other thoughts are quickly check auto wreckers tomorrow. Last resort order from VW and wait til the weekend at the earliest. In the meantime does anyone know if there’s a place on my car with the exact bolt I could “ steal “ for the time being and hat least get it back together ? Obviously off something of less importance. As well is this bolt gonna be some sort of specialized material or in some way that I should be avoiding just using one from a hardware store ? Sorry for all the questions! I’m just hoping to deal with this sooner than later as it’s not ideal to leave it in it’s current state in my garage for the next week waiting for parts
The shorter bolts will be fine...it's only 2mm (.079")...being an M6, it's likely a 1.0 thread pitch, which means essentially you'll be losing 2 threads on the bolt. That will be plenty good. When you get the flange back against the block, thread in one by hand, just maybe 1 or 2 turns so the bolt catches. Look at the distance now from under the head of the bolt to the surface of the flange the bolt/washer we be seated against...that's how much thread engagement you'll get. Should be more than enough.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
The shorter bolts will be fine...it's only 2mm (.079")...being an M6, it's likely a 1.0 thread pitch, which means essentially you'll be losing 2 threads on the bolt. That will be plenty good. When you get the flange back against the block, thread in one by hand, just maybe 1 or 2 turns so the bolt catches. Look at the distance now from under the head of the bolt to the surface of the flange the bolt/washer we be seated against...that's how much thread engagement you'll get. Should be more than enough.
Ok awesome thanks ! Do you recommend a thread lock like the blue stuff to avoid it vibrating out ? Or is this not a good idea ?
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Ok awesome thanks ! Do you recommend a thread lock like the blue stuff to avoid it vibrating out ? Or is this not a good idea ?
I rarely use loctite unless the FSM calls for it.
I'm an advocte or marine grease... That way you can get the bolts out in the future.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
I rarely use loctite unless the FSM calls for it.
I'm an advocte or marine grease... That way you can get the bolts out in the future.
Ok thanks all good! I reinstalled the flange tonight. the bolt in question seemed to work fine , tho I have yet to actually add coolant and fire up I ran out of time. I just minor lubed and torqued lightly by hand so we'll see what happens!

Below are pics of what the old o ring looked like and the new one in the flange before installation:


The old one was basically broke in 2 before even removing. So hope that was the issue and the new one works ! Next step is the seal between glow plugs and main flange . It seems fine but will replace anyway . You'll see in the one pic I never detached glow plug wires. I started but man they seem siezed on. I didn't want to open a can of worms given my recent troubles but any advice on removing boots and possibly replacing plugs just cause? The one plug seemed to be spinning within itself !
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Ok thanks all good! I reinstalled the flange tonight. the bolt in question seemed to work fine , tho I have yet to actually add coolant and fire up I ran out of time. I just minor lubed and torqued lightly by hand so we'll see what happens!

Below are pics of what the old o ring looked like and the new one in the flange before installation:


The old one was basically broke in 2 before even removing. So hope that was the issue and the new one works ! Next step is the seal between glow plugs and main flange . It seems fine but will replace anyway . You'll see in the one pic I never detached glow plug wires. I started but man they seem siezed on. I didn't want to open a can of worms given my recent troubles but any advice on removing boots and possibly replacing plugs just cause? The one plug seemed to be spinning within itself !
The glow plug boots can take a bit of force to "pop" off. Pretty common.

Yeah I think you found the source of your leak haha.
 

MOGolf

Top Post Dawg
Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
Any good hardware store should have proper bolts. You can always get a longer one, screw a nut or two on it all the way, clamp in a vise, cut the bolt to proper length with a Dremel tool (or equivalent), and then unscrew the nuts to ensure the threads are good at the cut end.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Any good hardware store should have proper bolts. You can always get a longer one, screw a nut or two on it all the way, clamp in a vise, cut the bolt to proper length with a Dremel tool (or equivalent), and then unscrew the nuts to ensure the threads are good at the cut end.
Thanks for this . I like your idea for cutting the bolt and backing nut off to ensure threads are good, I'll use that in the future!!
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
For some reason, auto parts stores rarely have a good selection of hardware.
Good call. They had to bring in the "wrong" bolts from another location but they worked so far. But leave it to auto makers to have odd bolt specs. There is a specialty nut and bolt place in here, in the past I've had bolts for my mustang I've taken in and they've flat out said we have nothing like that you need to go to Ford....
 

MOGolf

Top Post Dawg
Joined
Jun 27, 2001
Location
underneath something
TDI
2001 Golf GLS TDI Reflex silver, rough road suspension and steel skid plate, 2004 Passat Variant, Candy White, rough road suspension and geared balanced shaft module, and much, much more. 2016 LR RR HSE TD6, 2019 Jaguar I-PACE
For some reason, auto parts stores rarely have a good selection of hardware.
I have TrueValue and Do-it-Best hardware stores nearby that carry metric bolts, etc. The Do-it-Best is also in the same store as NAPA. If I don't find it in the NAPA section, I may find it in the hardware store section.

Even Home Depot, Lowes, etc., have sections of metric fasteners and some other specialty fasteners for vehicles. One does not always have to go to auto part stores.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
I have TrueValue and Do-it-Best hardware stores nearby that carry metric bolts, etc. The Do-it-Best is also in the same store as NAPA. If I don't find it in the NAPA section, I may find it in the hardware store section.

Even Home Depot, Lowes, etc., have sections of metric fasteners and some other specialty fasteners for vehicles. One does not always have to go to auto part stores.
Nice. I get a pretty good discount at Napa. It’s not a flat percent but varies and on some items it’s pretty substantial. Some items I’ll always go to VW depending on what it is.
Ha there’s actually a big truck stop not super far from me , I’ve got parts there in the middle of the night before in a bind ! Nothing major but sometimes hardware or wire or bulbs etc
 

Rrusse11

Veteran Member
Joined
Jan 23, 2014
Location
PA Deutsch Country
TDI
2002 Golf, 5spd; 05 Jeep CRD
Don't know if they've got Fastenal your neck of the prairies, but they've had the occassional odd ball bolt/thread combo I've needed. Not cheap, but they've had them. The local hardware stores around here deal with a lot of farmers, one in particular has a really great selection, lots of farm equipment these days are metric. Galvanized bolts by the pound.
OT, but relevant, the best selection and prices on Stainless Steel is Albanycountyfasteners.com.
 

WolfgangVW

Veteran Member
Joined
Oct 16, 2011
Location
Alberta, Canada
TDI
2003 Jetta TDI - Manual
Don't know if they've got Fastenal your neck of the prairies, but they've had the occassional odd ball bolt/thread combo I've needed. Not cheap, but they've had them. The local hardware stores around here deal with a lot of farmers, one in particular has a really great selection, lots of farm equipment these days are metric. Galvanized bolts by the pound.
OT, but relevant, the best selection and prices on Stainless Steel is Albanycountyfasteners.com.
Thanks for this there is a fastenal here ! I will keep that in mind !
 

Jr mason

Veteran Member
Joined
Oct 20, 2013
Location
Ohio
TDI
01 Beetle, 2012 Jetta
Torquing dry fasteners is a bit of a misnomer. With no lube you are creating a false resistance of metal to metal which leads to improper gasket stress/clamping force. The torque wrench is looking for a predetermined resistance and doesn't distinguish drag from metal on metal contact versus the required gasket stress/clamping force you are trying to achieve.
Aside from that you also risk the possibility of galling. More so on fasteners that are subject to repeated heat/cool cycles or installed/removed frequently. Some applications call for a specific lubricant. Believe it or not loctite is a lubricant and proper application over the entire bolt, not just a few drops is important to ensure proper thread lubrication, and therefore tension. Manufacturers take into account for this coefficient when they call for a fastener to be loctited.
For all other applications that don't call for a specific lubricant I would strongly recommend picking a type and researching the coefficient. Being I'm in the rust belt I use anti seize on pretty much everything that doesn't call for Loctite (not including internal engine/drivetrain components). My go to is Chesterton 725 Nickel. I came to this after trying several different brands and types over the years both copper and nickel based. The 725 has a very consistent viscosity over a wide range of temps. It doesn't turn to peanut butter in the cold. I've come to use it on caliper pins and slides as it is very good at resisting water wash off.
And most importantly for torquing fasteners it has a 0 torque coefficient. This is critical to remember because most anti seizes and other lubricants have a large coefficient. I've seen some copper formulas - I think from Bostik- with a over a .3 (30%) torque coefficient. SAE 30w oil is around .35 for reference.

https://www.bbcpump.com/wp-content/...hesterton-725-Nickel-Anti-Seize-Datasheet.pdf
 
Last edited:

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
Torquing dry fasteners is a bit of a misnomer. With no lube you are creating a false resistance of metal to metal which leads to improper gasket stress/clamping force. The torque wrench is looking for a predetermined resistance and doesn't distinguish drag from metal on metal contact versus the required gasket stress/clamping force you are trying to achieve.
Aside from that you also risk the possibility of galling. More so on fasteners that are subject to repeated heat/cool cycles or installed/removed frequently. Some applications call for a specific lubricant. Believe it or not loctite is a lubricant and proper application over the entire bolt, not just a few drops is important to ensure proper thread lubrication, and therefore tension. Manufacturers take into account for this coefficient when they call for a fastener to be loctited.
For all other applications that don't call for a specific lubricant I would strongly recommend picking a type and researching the coefficient. Being I'm in the rust belt I use anti seize on pretty much everything that doesn't call for Loctite (not including internal engine/drivetrain components). My go to is Chesterton 725 Nickel. I came to this after trying several different brands and types over the years both copper and nickel based. The 725 has a very consistent viscosity over a wide range of temps. It doesn't turn to peanut butter in the cold. I've come to use it on caliper pins and slides as it is very good at resisting water wash off.
And most importantly for torquing fasteners it has a 0 torque coefficient. This is critical to remember because most anti seizes and other lubricants have a large coefficient. I've seen some copper formulas - I think from Bostik- with a over a .3 (30%) torque coefficient. SAE 30w oil is around .35 for reference.

https://www.bbcpump.com/wp-content/...hesterton-725-Nickel-Anti-Seize-Datasheet.pdf
I'm going to address the first sentence.

Manufacturers torque specs are for bone dry hardware, not lubed. They are assembled at the plant dry, and those assemblies have to meet engineering drawings on the line. If they lubed a bolt that wasn't supposed to be and quality control caught it, it's a non conformance.

Only when they call for it (with loctite or similar) is that value baked in.

So, by adding any type of lube, you are changing the friction coefficient, which will increase your torque. You will be overtorqued in the situation where you use lube.

As far as anti-seize recommendation, if I were to use it, that would be my go to. It doesn't get hard and brittle like the cheap stuff, but that nickel based stuff is EXPENSIVE. I switched many years ago to Evinrude triple guard grease. It's made for the harshest marine saltwater environments. I've spun nuts off screws, and bolts out from 5 years ago on my truck and they came off like butter. Same with the boat. I do drop my torque values about 20% when using it.
 

Jr mason

Veteran Member
Joined
Oct 20, 2013
Location
Ohio
TDI
01 Beetle, 2012 Jetta
I'm not sure what your addressing? I did specifically state to "pick something and find the torque coefficient" and that it is critical to remember this when using.

I would encourage anyone to find one article from SAE or ASME that encourages the assembly of dry fasteners where torquing is critical. Specialty applications not withstanding such as PTFE coated or CL2 or O2 service, etc.


Just because they assembled them dry at the factory doesn't mean anything other than they didn't want to take the time to do it right. Particularly where a fastener is threaded into a dissimiliar metal.
Using a lube with the correct torque coefficient doesn't change the torque rating. Just sayin.
 

KrashDH

Top Post Dawg
Joined
Dec 22, 2013
Location
Washington
TDI
2002 Golf
I'm not sure what your addressing?

1) See italics below

2) Just because they assembled them dry at the factory doesn't mean anything other than they didn't want to take the time to do it right. Particularly where a fastener is threaded into a dissimiliar metal.
1) "With no lube you are creating a false resistance"

It's the other way around. But there are equations that take care of every situation, and it depends on application


2) Absolutely incorrect. I'm a mechanical engineer at an aerospace company that has to design things on the daily that use every kind of fastener spec that you can imagine, as well as lubes most people in the industry haven't even heard of. My designs incorporate all sorts of preload and clamping pressure requirements, sometimes which means designing custom hardware. Our assembly drawings REQUIRE torques be placed on the drawings and based on our equations, lube types have to be called out if applicable, minimum thread engagement, maximum load capacity, etc. One can't simply "ignore" the drawing because they don't feel like "taking the time" to do it. it doesn't work that way.

As well, I have co workers in my group currently who have been with previous companies (Toyota and Honda) that were design engineers. There are hundreds of assembly drawings for these vehicles. Their technicians adhere to these engineering drawings. If they don't, one non-conformance such as a mere little bolt that was/wasn't lubed, ends up costing the company a lot of money and engineering time just for paperwork, root cause analysis, etc. Not because it's hard to solve, but because everything has to have a paper trail and documented. Bolts are simply assembled dry because cost. Engineers design requirements are based on dry-dry contact unless it's critical (where you'll see the addition of loctite or similar in the FSM.)
 

Jr mason

Veteran Member
Joined
Oct 20, 2013
Location
Ohio
TDI
01 Beetle, 2012 Jetta
"Bolts are simply assembled dry because cost"

That's my point. Your veering off on applications that qualify as the specialty application I keep mentioning, even though you admittedly use some form of lube as well. There is a reason for this and it comes down to achieving the proper clamping force while maintaining the integrity of the fastener and not going beyond it's intended yield. Those last two are often seen with dry fasteners, particularly when assembled/disassembled often.


I also very much disagree with your assessment that lube causes a false torque. If a lubed fastener requires less torque to achieve a specified clamping force than a dry fastener, where is the extra energy being applied in the case of the dry fastener?

Most standards assume a "dry torque" and therefore calculations are required for some (not all) lubes. This in no way defines dry assembly as being preferable, or better for the longevity of the fastener. Lube prevents galling and corrosion that dry fasteners are subjected too. One just must know and understand the effect the lube has on the final torque as I've noted above.
 
Top