Adjustable Torque Wrench

For many vehicle maintenance and repair applications, a torque wrench is a must. Having the right tool for the job means getting the job done right.

There are three basic types of adjustable torque wrench for manual use. All of them have some sort of mechanism for setting the desired torque value for use and a means of alerting the operator that they have reached that value.

Click Wrenches

These are the most widely-used and common of the adjustable torque wrenches on the market. The operator sets a torque value and then puts the wrench into play on the application. When the desired torque is reached, an audible "click" is heard and often accompanied by a short (3-5 degree) "break" where the handle releases from the wrench head for a moment.

After that, the wrench continues to function normally and for this reason, training and care is required when using a click wrench. It's still possible, after the indicators, to continue putting torque on the application.

Break-Over Wrenches

These operate in the same way, but come in two types: automatic and manual reset. The user sets the desired torque value and applies the wrench to the application. When the desired torque is reached, the wrench "breaks" and goes limp by separating the handle from the wrench head for 20-90 degrees.

Automatic resetting break-over wrenches are automatically reset when the break is either accompanied by a return stroke back to the original break point on the head or followed by a lack of pressure on the handle. Manual break-over wrenches require the operator to remove them from the application and physically reset the wrench.

Cam-Over Wrenches

Are similar to break-over wrenches except they use a ball and lobe design to cause the wrench to slip free of the application once torque is reached. This prevents any chance of over-torque, which is why these are the most commonly used wrench designs for production applications. They are often air or electrically-driven.

Dial Wrenches

Are also common in quality control applications. They are not commonly used in mechanics or production, but are usually used to check and test torque that's already been applied such as after a production line segment has been reached.

Using the Proper Wrench

The proper adjustable torque wrench for your application is essential for success in your automotive repair. The mechanic should ensure that he or she has the right tool for the job, which often means having more than one torque wrench.

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