Quote:
Originally Posted by dwightdi
At one time I worked for NASA. They established these specs. by measuring the extension of the studs and therefore determined the exact stress on the assembly. Using lubricant allowed them to reduce the frictional variance and improve the repeat-ability of the resultant stress. Airstream and the car companies develop their torque specifications without lubricant. Using lubricant on the treads and the torques specified by the dry experiments will result in over stressing and damaging the studs. If you want to use lubricant, then you will have to conduct your own tests to establish new lower torque values that will be required to have the studs to remain in the proportional range stress and resulting in stresses that are 80 to 90% of the yield strength of studs. Personal note: It is easier to follow Airstream's engineering department recommendations and do not use lubricant.
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Good poop Dwight!
Yes, stretch and twist of bolt during assembly can allow "over stress"..
This reminds me of Harley Torque specs,,,... Tighten until it juuuuuuuuuuuust starts to twist OFF, then back off 1/4 turn.
Seriously, AS is working with NEW parts, so ideal for establish of specs.
I am with Panheaddave. I do NOT totally coat the threads but they do get a wipe and little dab. I then run lug nuts in/out to ensure even coat and ZERO binds. The real holding power of the lug nut is where it mates to the wheel.. That is where most "torque" will be absorbed. Not the threads.
But, this is like making coffee... If you are happy and like the taste, "Carry On!"
Peace
Channing