Quote:
|
Originally Posted by Picasso
I can't imagine that your torquing of a stud to 140 ft/lbs alone broke it. Something else must have contributed to its failure before you touched it. Maybe it was defective.
|
When CORRECT torque is applied to a stud the stud itself stretches - that's how it works.
The degree of "stretch" is engineered. Over tightening the stud causes PLASTIC deformation of the stud (big words for " stretch permanently, change stud metal characteristics at the microscopic level in a bad way")
Studs that are correctly torqued (stretched) have a duty cycle as well (they change permanently over time). Racers change certain bolts/studs after each torque cycle!
BOTTOM LINE - yes, over torque is BAD all of the time - gone are the days of "over engineering" that allowed this kind of abuse of torque values!
The field of engineering that deals with this is Finite Element Analysis for those with way too much spare time ;-)
P