Years ago one of my friends (who never used a torque wrench as a matter of principle) would respond to anyone who asked him a torque spec with "I simply tighten it until it breaks and then back off half a turn"...  A strange joke but had some truth which is probably the reason he was a master at repairing threads and removing broken bolts and studs. 

My gramps apparently buggered up stuff up all the time. All he ever told me was “a cross thread is as good as a lock washer!”