When it comes to automotive maintenance and repair, a torque wrench is a staple instrument to have in your tool box. Continue reading to learn about torque wrenches, including the common types to choose from and some tips on how to use one.
What Does a Torque Wrench Do?
Torque wrenches measures the amount of torque; right? Well, yes, but more specifically, they measure the amount of rotational force (turning) applied to a threaded fastener (nut or bolt). This force is referred to as “torque”, and is a common measurement used in many industries, especially the automotive field.
Not all torque wrench scales read the same, as some are in English and some are in metric format. Most, however, are now designed with dual scales that read in both English and metric formats. Common formats include foot – pounds, inch – pounds, and Newton – meters.
An example: 1 foot-pound = 1 pound of pull on a lever that is 1 foot long
Types of Torque Wrenches
Although there are countless torque wrenches to choose from in terms of brand, size, and quality, there are 3 fundamental types you will find on the market. These include dial indicator torque wrenches, sound-indicating torque wrenches, and flex bar torque wrenches.
Dial Indicator – Dial indicator torque wrenches are similar to flex bar wrenches because they also come with a visual display that specifies the applied torque. They are also respected for the quality control in monitoring and verifying torque measurements.
Sound-Indicating (micrometer) – Sound-indicating torque wrenches are also known as micrometer wrenches, which is no surprise since they read on a micrometer scale. When the preset torque value is achieved, they make an audible clicking noise by briefly releasing the wrench a few degrees.
Flex Bar – Flex bar wrenches are also known as “scale” or “beam” torque wrenches, which are effortlessly distinct from one another by their stationary needle that runs along the length of the shaft handle. The needle visually reads the applied torque against a scale at the base of the handle.
Tips for Using a Torque Wrench
If you have an adjustable torque wrench, set it at its minimum reading when it is not being used; otherwise, the accuracy of its readings will be jeopardized. Furthermore, never apply torque past its release point. This can over-tighten your thread.
With sound-indicating wrenches, be sure to get familiar with what the release click feels like in case your shop is too noisy. When on the lower settings, the click can be hard to hear in a loud environment.
It is recommended to reserve your torque wrench strictly for torque wrench uses. Using a torque wrench as a pry bar or disassembly tool can damage its quality and accuracy.
For flex bar or dial indicator torque wrenches, always read an indicator with a straight-on view of its surface and while holding them at the center of their handle grips. This will eliminate the risk of errors.