Nuts

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rambojoe

Senior Member
Location
phoenix az
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Wireman
Dont lube machine threads unless you really want them to break free. Soap up your deck screws all you want.
 

Sberry

Senior Member
Location
Brethren, MI
Occupation
farmer electrician
Dont lube machine threads unless you really want them to break free.
They will never tighten correctly dry. Wheels oin trucks come loose all the time due to the fact they were not properly clamps despite the fact the bolt stopped turning. Torque does not measure clamping power, its only resistance to turning, quits turning, connection not tight. And you do want them to break free when its time to remove them.
 

Sberry

Senior Member
Location
Brethren, MI
Occupation
farmer electrician
Snapon torque wrench manual of the 20's said,,, all values based on clean lightly lubricated threads.
 

Sberry

Senior Member
Location
Brethren, MI
Occupation
farmer electrician
So, that's a twofer.
Yes it is. Its often used where the joint cant be tightened or clamped, a tapered connection like a ball joint or tie rod where they traditionally use an additional keeper. Yes, other places too/ Used a lot where its difficult to control the labor.
This and how threads and fasteners work is not very well stressed in trade schools. I havnt read all the courses, only course publication I have saw and its a book included in their package is John Deere, I am sure Cat and others do the same. Its mentioned a bit in Ironworkers material but really mostly in engineering. Threads are a ramp,,, its why they grease the slides.
I have seen an early forum on this, just too narrow and too boring for most people that it didnt last.
 

Sberry

Senior Member
Location
Brethren, MI
Occupation
farmer electrician
That doesn’t make sense. The accuracy of the torque measurement of the wrench cannot be affected by what’s being torqued.
They were simply stating that they wanted clean lightly lubed threads, no it doesnt change the tool but they listed all the pitch and grade fasteners with a recommended torque. Applying 50# to a dirty rusty or even simply dry thread will result in a different clamp pressure. Really greatly,,, hugely effects the start or restart torque.
Think about this. say guyy one puts a wire under lug, lubes and tightens firm and wants to come back and snug it, reinstall, any reason wants to move this connector. If its seized or stuck who knows what the torque will be, either direction, can even be seized immediately upon installation. First guy can turn it a bit either way, if it happens to be loose can simply tighten it a little again, with or without a torque wrench.
It may never tighten dry and some threads take 8x dry to turn it as lubed.
 

retirede

Senior Member
Location
Illinois
They were simply stating that they wanted clean lightly lubed threads, no it doesnt change the tool but they listed all the pitch and grade fasteners with a recommended torque. Applying 50# to a dirty rusty or even simply dry thread will result in a different clamp pressure. Really greatly,,, hugely effects the start or restart torque.
Think about this. say guyy one puts a wire under lug, lubes and tightens firm and wants to come back and snug it, reinstall, any reason wants to move this connector. If its seized or stuck who knows what the torque will be, either direction, can even be seized immediately upon installation. First guy can turn it a bit either way, if it happens to be loose can simply tighten it a little again, with or without a torque wrench.
It may never tighten dry and some threads take 8x dry to turn it as lubed.

The intent of torquing to a certain value is to put the fastener into a given state of tension. For a tool manufacturer to recommend “lightly lubed” without specifying a host of other conditions is just nonsense.
 
Applying 50# to a dirty rusty or even simply dry thread will result in a different clamp pressure
Lots of torque specs either say or assume "clean dry threads". Unless the spec says to lube, well, why would you?

Try this http://acversailles.free.fr/documen.../Visserie/The_principles_of_thread_torque.pdf

Or this https://pscorp.ph/wp-content/uploads/2019/06/ALL-SPM-CH02-Torque.pdf (from Bell Helicopter)
The first page prominently says
ALL TORQUE VALUES APPLY TO DRY
THREADS. DO NOT USE THREAD
LUBRICANT OR ANTI-SEIZE
COMPOUND UNLESS SPECIFICALLY
CALLED FOR IN THE APPLICABLE
MAINTENANCE PUBLICATION.
 

rambojoe

Senior Member
Location
phoenix az
Occupation
Wireman
The intent of torquing to a certain value is to put the fastener into a given state of tension. For a tool manufacturer to recommend “lightly lubed” without specifying a host of other conditions is just nonsense.
Fair enough but the end result is the availible stretch of the stud- which is why we always snap grade 5 (or worse,grade 3) 1/4-20 bolts in gear...
One fellah wanting praise for his first main gear and he had g.5 on the lugs... No one cared.
 
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