The reason for degree of rotation torque spec is that some ppl are stupid and get oil, antisieze, or some other type of substance on the threads and the torque is no longer accurate. With degrees of rotation the torque is consistent every time.

 

Ditto what 96ws6 said.


Also, ALL bolts stretch. that is how they provide the clamping forcethat keeps our junk together

 

using a torque angle meter is the only accurate way us in the trenches have of ensuring that the tty bolt in question has been spun enough to put the "yield" into tty. merely using an arbitrary torque spec . isnt going to ensure that the bolt has given its all in the quest for perfect sealing. engineers know that x degrees of rotation is x dimension further into the block and thats all figured by the thread pitch in the block deck and how far the head bolt goes in a turn-(or a percentage of a turn)

 

I use a tq angle meter everytime. Works great, just a PITA...Cory