Torque wrench basics
If you have a boat trailer or have changed the spare tire on
your car, a torque wrench is a required tool and is simple to
use . Most people believe that "the tighter the better" is the
way to go. Your average person will simply grab an impact wrench
and tighten away. This is not the correct way to apply torque to
your wheels or other critical fasteners. Too much torque can add
stress to a lug nut and cause it to shear off. Also with head
bolts, the torque on those bolts determines the amount of
clamping force on the gasket. Over tightening those bolts can
crush the gasket or distort the metal. The better way to apply
the correct amount of foot pounds of torque is to use an
accurate torque wrench. There are several different types of
torque wrenches available out there. One type is the torque
wrench with a dial indicator built into it. The dial indicates
how many foot lbs of torque is being applied. Dial types are
generally more accurate and easier to read. This model is
generally the choice of professional mechanics where accurate
measurement is necessary. The dial indicator is more precise and
is easier to read. Some are available with a light or buzzer to
indicate when a preset torque value is achieved. Another
variation is the clicking type torque wrench. These are probably
the most popular and readily available. This torque wrench makes
a clicking sound when the preset torque is reached. This lets
you know to stop applying force to the nut you are fastening and
move to the next one. For most uses these type of wrenches work
just fine and are rugged and easy to use. For the person who
always the latest gadget, there are LED and LCD models available
as well. The display shows the precise foot lbs of torque. These
can usually switch between SAE and Metric as well. For most
garage mechanics and home owners, the clicking type torque
wrench is the best choice. Just remember to always check the
manufacturer specs for the recommended torque. Next time, you
need to tighten the nuts on your boat trailer, put down the
impact wrench and grab a torque wrench.