Matt reckoned:
> My thought was that some of the torque
>applied is ``used up'' overcoming the friction of the nylon against
>the threads as the fastener is tightened. (I.e. you cannot spin a
>nylok nut down a stud like you can a regular steel nut.)
And you were correct . . however, the extra torque would be negligible on
a "nyloc". There ARE industrial fasteners which operate on the principle of
deformed nut bodies or threads which would require factoring in the extra
torque if NASA style accuracy was required. The quick answer to you querry
might be to suggest that you should determine the torque the locking-type
fastener requires by measuring the torque exerted BEFORE shoulder contact is
made . . . then adding those inch-pounds, etc., to the specified value.
Tony
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