Choose the Optimal Range
A torque wrench is an essential tool for proper automotive or bicycle maintenance. Such wrenches allow the operator to choose the exact torque, or twisting force (measured in inch-pounds or foot-pounds), applied to each screw, bolt, or fastener.
Since the nuts and bolts on a car or bike must be tightened to exact specifications, a torque wrench ensures a mechanic does not damage a bolt by applying too much torque. Torque wrenches are superior to regular ratchet wrenches when tightening fasteners, as they allow for greater precision.
However, with so many types of torque wrenches, it may be daunting to seek out the right torque wrench for each job. The following tips will not only show you how to pick the perfect torque wrench for each task, but also how to operate it correctly, hold it properly, store it safely, and recalibrate it for accuracy.
Listen for the Click
Torque wrenches have an adjustable spring-loaded lever. When using the wrench, you set the desired torque reading by twisting the wrench handle. Once you achieve the amount of twisting force you need on a bolt or nut, the spring-loaded lever cuts loose and produces a clicking sound to let you know you can stop twisting.
However, a torque wrench will continue turning the bolt, nut, or fastener even after the click. If the user doesn’t hear the click, they may continue applying torque, especially when using a torque wrench at the low range.
To prevent this from happening, make sure to use a torque wrench in the optimal range and stop twisting when the wrench clicks. If you keep pulling the wrench, you risk over-torquing the fastener and damaging it.
Use the Correct Grip
To ensure that you apply the correct amount of torque to a bolt, nut, or fastener, make sure to grip the torque wrench correctly. Hold the wrench with the palm of your hand in the middle of the handle when applying force.
If you hold the torque wrench at the end of the handle, the amount of torque may be less than what you need, even if the wrench is preset to apply a specific amount of torque. Likewise, if you hold the torque wrench too close to its head, you may apply too much torque.
Store Your Wrench Correctly
When not using your torque wrench, be sure to turn the wrench down to its lowest possible setting. If you store a torque wrench at a higher setting, your wrench’s main spring can wear out and eventually fail.
Make sure to also avoid storing your wrench in places with extremely high or low temperatures or high humidity. Ambient moisture will cause your wrench to corrode.
Recalibrate Regularly
Like every torque tool, a torque wrench will suffer wear and tear with general use. A frequently used torque wrench will eventually fall out of calibration and deliver more or less torque than you want it to.
Those who continue to use an improperly calibrated torque wrench might accidentally over-tighten nuts and bolts, damaging or breaking the fasteners. Similarly, a torque wrench that delivers less torque may leave nuts and bolts too loose, making it possible for the wheels of a car or bicycle to fall off.
To make sure your torque wrench is properly calibrated from the beginning, it’s a good idea to purchase torque tools with a certification of calibration traceable by the National Institute of Standards and Technology (NIST). After a year — or 5000 clicks — it’s considered standard practice to get your torque wrench recalibrated. Recalibration will ensure your wrench is accurate and can continue to provide high-quality results when tightening nuts and fasteners.