torque wrench is a tool that is used to indicate and precisely set
the amount of force being applied to a fastener such as a nut or
bolt. A torque wrench usually takes the form of a socket wrench
with a special internal mechanism. The type most commonly used for
automotive jobs is the clink wrench.
A torque wrench is used where the precise tightness of screws and
bolts is crucial. The specs for a particular fastener can be obtainer
from the manufacturer's service manual. On a click-type torque wrench,
the specified torque is set on the wrench handle and the proper
size socket snapped onto the wrench drive. When tightening a series
of fasteners, such as the nuts on a wheel, the recommended sequence
and gradation of tightenings should be followed until the specified
torque is achieved on all the fasteners.