I am not certain exactly what tolerance
is on the wrench, but it is generally agreed
that the tolerance on the actual tension of
the bolt is approximately 25 percent. I think
this means that if you are torqing to 75 percent
of yield on the bolts, you may end up with 50 percent
to 100 percent. The 75 percent that is used
is based on the torque wrench ranges. If you
are tightening by other methods with tighter control
you can torque to higher values i.e. 100 percent
minus one half the tolerance to ensure that you
do not reach 100 percent.