Torque Control 2
A major question today is how much torque should be used to properly tighten a fastener. As simple as
this question may seem, the answer depends on a variety of factors. It is estimated that roughly 90% of the input energy is lost in overcoming the mating friction under the head and between the thread or nut and its mating threads. Consequently only the remaining 10% of input energy is turned into bolt stretch. Bear in mind that this is an oversimplification of what may actually happen, since no consideration is given to the various forms of heat and strain energy introduced into the system.
