Originally Posted by
UniChris
That's kind of... half right, and half wrong.
The clamping force depends on material, but the torque required to produce a given clamping force very much depends on both the diameter and thread pitch of the screw.
But it also depends on things like if the threads have been lubricated with a grease or anti-seize...
Correct but.....given the near universal use of M5x0.8mm clamping bolts makes the recommended torque a useful value. Of course lubrication does matter but I hope most mechanics know to grease these bolts to avoid corrosion if for no other reason.