Using a Torque Wrench

Using a torque wrench correctly involves three primary concerns.

Use a smooth even pull to the stopping point. Jerking the wrench can cause the pivot point to break early. Not stopping when the wrench “clicks” will cause it to over torque. Do not turn past the click

When more than one bolt holds the surfaces together there is normally a sequence that should be used to bring the surfaces together in an even manner. Sometimes this is simply a “criss-cross”, but sometimes the maintenance manual will have a numbering scheme – if so it should be followed. Just starting on one side and going in a circle around the part can cause the part to warp, crack, or otherwise cause damage.

In some cases the maintenance manual will require the threads be lubricated prior to tightening the bolt. Whether a lubricant is used or not has a considerable impact on how much torque is required to reach a given preload. Use lubricant if required, or not if so specified. If you don’t follow this pint you’ve wasted your time using a torque wrench.

Caring for Your Torque Wrench

Unlike a hammer or crow bar, a torque wrench is a precision instrument and needs proper care. If it feels like a bolt is not getting tight enough by using your torque wrench, have the wrench tested. If you need to remove a bolt, set the torque wrench aside and use a different tool. The clockwise/counterclockwise switch is for using the torque wrench on either clockwise or counterclockwise threaded bolts, not for removing a bolt or loosening it so you can re-torque. Lastly, store your wrench where it won’t be bumped around.