Torque Wrench Limitations: Accuracy and Range

The accurate application of torque is essential when fastening and loosening nuts, bolts, and other components. Knowing the limitations of your tool helps ensure quality and safety during the process. Understanding how torque wrenches work and what their accuracy range means can help everyday mechanics as well as industrial professionals use their tools effectively.

In this blog post, we’ll explore the limitations of hydraulic torque wrenches and how they affect accuracy and range.

What is a torque wrench?

If you’ve ever worked on any type of machinery, you’ve probably heard of a torque wrench. But what is it exactly? Simply put, a torque wrench is a tool that allows you to tighten nuts and bolts securely without over-torquing them. They measure and apply a specific amount of torque to the fastener or bolt, which is determined by the size, shape, material, and application of the nut/bolt. 

By using a torque wrench, you can ensure the desired force is applied and that the fastener or joint does not become loose over time. This is important because different applications require varying levels of torque, and over-tightening can damage the equipment while under-tightening can lead to unsafe conditions.

How torque wrenches work

The torque wrench operates by allowing the user to set the desired level of torque, and then the wrench will click or release when that level of force is reached. This way, you can be sure that your fasteners are tightened to the appropriate level every time.

Torque Wrench Types

Different types of torque wrenches are available for different applications, including hand-held and digital models:

• Manual torque wrench: A manual torque wrench has a handle that the user turns to apply force. It is designed to click or release when the desired torque level is reached.

• Digital torque wrench: A digital torque wrench measures and displays the amount of torque being applied in real-time, allowing for more precise operation.

• Hydraulic torque wrench: A hydraulic torque wrench is powered by a hydraulic driven pump (air or electric) & uses hydraulics to deliver the required amount of force. These are often used for industrial applications.

• Pneumatic torque wrench: A pneumatic torque wrench uses compressed air motor and a gear box to deliver the required amount of force, making it ideal for tightening and loosening larger fasteners in a quicker way compared to a hydraulic or manual wrench.

• Battery-powered torque wrench: A battery-powered torque wrench is a gearbox driven torque wrench that allows you to change the torque through  digital display. The ability of of the battery powered aspect now allows industrial torque jobs to be handled anywhere regardless of power supply.

• Electric torque wrench: An electric torque wrench uses electricity to power the motor and deliver the required amount of force through a planetary gear system.

Accuracy and Range Limitations

The accuracy of a torque wrench is limited by tool model, please confirm your accepted tolerance before choosing a tool. When selecting a torque wrench, it is important to check the accuracy range of your tool and ensure that it will meet the requirements of your application.

Calibration

Calibration is important for torque wrenches, as incorrect calibration can cause the readings to be inaccurate.To ensure accuracy, it is recommended that you check your torque wrench against a known standard regularly or atleast perform spot checks internally. 

Accuracy range

Every wrench operates within a given accuracy range, such as ±2-4% over 20% to 100% of full-scale. Knowing what these numbers mean and how they affect torque wrench accuracy

is important when using a torque wrench.

Torque wrench range

As well as the torque wrench accuracy range, they are also manufactured in given torque ranges. Before selecting a torque wrench, you should understand the torque range you need for your applications. For example, a small bolt may only require 2-5 Nm of torque, while larger bolts may require higher amounts. However, you may need more than one torque wrench of varying torque ranges to cover all your applications and meet the desired torque wrench accuracy levels.

Environmental factors

Torque wrench accuracy can also be affected by environmental factors such as temperature and humidity. Proper lubrication is also important for torque wrenches, as this ensures that the threads are clean and free from dirt or debris, which may affect accuracy.

Ways to Increase Torque Wrench Accuracy 

To ensure torque wrench accuracy, there are several steps you can follow:

• Stick To the Torque Limit: It is important to stick to the torque limit specified by your manufacturer as exceeding this could damage or weaken the fastener.

• Use the Marked Loading Point: It is important to use the marked loading point on the torque wrench, otherwise you may be applying too much force.

• Check Your Wrench Regularly: Check your wrench regularly against a known standard, such as a calibrated torque gauge, to ensure accuracy.

• Use A Quality Wrench: Always use a quality torque wrench that is appropriate for the job.

• Follow the Instructions: Make sure to follow the manufacturer’s instructions carefully to understand torque wrench settings, as this will help ensure accuracy and prevent damage to the tool or fastener.

By following these steps, you can increase the accuracy of your torque wrench and make sure that your job is done correctly.

Tips for Maintaining Your Torque Wrench for Long-Term Reliability

Maintaining your torque wrench is essential for ensuring long-term reliability and peak performance. Some useful tips include:

• Store Properly: Always store your torque wrench in a dry and secure place, preferably in its original packaging.

• Clean Regularly: Clean the threads of the wrench regularly with a lubricant or cleaner to prevent dirt and debris from affecting torque wrench accuracy.

• Inspect for Damage: Inspect the entire tool for any damage or wear on a regular basis. If any damage is found, replace the wrench immediately.

• Calibrate Regularly: As already mentioned, have your torque wrench calibrated regularly by an accredited calibration service provider to ensure accuracy.

Conclusion

Torque wrenches are essential tools for accurate and precise fastening applications. To ensure torque wrench accuracy, it is important to understand the accuracy range of your torque wrench, use the marked loading point, stick to the manufacturer’s torque limit, check your wrench regularly against a known standard, use a quality wrench, and follow the instructions carefully when using a torque wrench.

Regular inspection and maintenance, as well as calibration by a trusted service provider, are also important to ensure the long-term reliability of your torque wrench. By following these tips, you can ensure torque wrench accuracy.

Browse Torque Wrenches at ALLTORC Today

At ALLTORC, we offer a wide range of torque wrenches and other tools for your fastening applications. From hydraulic to pneumatic and manual torque wrenches, our selection is sure to meet your needs at unbeatable prices. What’s more, we offer repair and calibration services, so you can be sure that your tools are up to par and ready for the job.

Shop with us today and get access to quality torque wrenches and other fastening solutions! Contact us today for more information.