Torque Wrench Calibration: Why It’s Important and How to Do It

Torque wrenches are indispensable in various fields, including automotive repair, construction, and manufacturing. They can apply precise torque levels to fasteners, ensuring that bolts, nuts, and other components are securely fastened. A torque wrench must be calibrated properly to maintain accuracy like any other precision tool.
Calibration ensures instrument reliability and increases workplace safety. In this blog post, we’ll explain why calibrating your torque wrench is important and offer step-by-step instructions on how to do it.
Why Torque Wrench Calibration is Important?
Ensures Accuracy
Torque wrenches are designed to help you find the precise torque measurements for the job at hand. Over time, constant usage, wear, and environmental conditions can cause a torque wrench to lose its precision. An uncalibrated wrench may under-tighten or over-tighten bolts, resulting in incorrect torque settings that may compromise the functionality and safety of the equipment it was used on.

Promotes Safety
Incorrect torque may result in dangerous situations. Bolts that are not tightened enough may loosen and cause parts to come apart, whereas fasteners that are too tight may break or damage components. The dangers in both circumstances include mechanical failure, industrial mishaps, and injury. You can prevent these risky situations by properly calibrating your torque wrench.

Prolongs Equipment Lifespan
Accurately secured fasteners guarantee that equipment and machinery run smoothly, eliminating wear and tear caused by over- or under-tightening. This helps extend the machinery’s life, saving money in the long run and decreasing the need for expensive repairs or replacements.

Meets Compliance Standards
There are strict standards for torque applications in many industries, especially in the automotive, aerospace, and manufacturing sectors. Calibrating torque wrenches regularly ensures compliance with industry regulations and prevents legal and financial consequences due to non-compliance.

How Often Should You Calibrate Your Torque Wrench?
The calibration frequency is decided by how frequently the wrench is used, the environmental conditions it is exposed to, and the manufacturer’s recommendations. Most manufacturers recommend calibrating your torque wrench at least once a year. However, in high-usage or precision-critical applications, calibration may be necessary more frequently—every six months or after a specified number of uses.
How to Calibrate a Torque Wrench: A Step-by-Step Guide
Before you begin: Calibration should ideally be done with a professional torque tester or calibration machine. If you don’t have one, consider sending your torque wrench to a certified calibration service.
Step 1: Gather Tools and Materials
- Torque wrench.
- Calibration device (torque tester or calibration machine).
- Manufacturer’s specifications for your torque wrench.
- Adjustment tools (e.g., screwdrivers or wrenches) as required for your specific model.
Step 2: Set the Torque Wrench to Its Lowest Setting
Start by setting your torque wrench to the lowest torque value. This ensures that the wrench starts in a neutral position and provides a baseline for calibration.
Step 3: Attach the Torque Wrench to the Calibration Device
Secure the torque wrench in the calibration device according to the manufacturer’s guidelines. Check that it is properly positioned to avoid false readings.
Step 4: Test the Torque Wrench at Different Settings
Use the calibration device to provide the wrench a specific amount of torque. Begin with testing at the wrench’s lower capacity, then progress to the mid-range, and lastly to the upper end of the scale. This guarantees that the wrench remains accurate throughout its range.
Step 5: Compare the Readings
Check the torque wrench readings against the calibration device readings. If the torque wrench consistently deviates from the calibration device, it indicates that it has to be adjusted.
Step 6: Make Adjustments
Most torque wrenches can be adjusted with a set screw or equivalent mechanism. Refer to your wrench’s user manual for information on modifying the internal spring mechanism to return the wrench to its proper calibration. Make minor modifications and retest the wrench to check that it is giving accurate results.
Step 7: Record the Calibration Results
After calibrating the wrench, record the date, testing values, and adjustments made. Logging calibration data lets you track the tool’s performance and stay on top of future recalibration.
Step 8: Mark the Wrench as Calibrated
Some industries require tagging tools with the calibration date and the technician’s initials. Use a permanent marker or an appropriate tag to designate the wrench as calibrated. This helps identify the tool as accurate and ready for usage.
Calibrating your torque wrench is important in ensuring your operation’s precision, safety, and efficiency. Taking the time to calibrate the instrument regularly will help you avoid accidents, increase the life of your equipment, and ensure compliance with industry requirements. Follow the techniques mentioned above to keep your torque wrench functioning properly, providing you confidence in any activity that demands exact torque application.
FAQs
Why is torque wrench calibration important?
Calibration is important because it ensures that the wrench produces the correct torque value, preventing under-tightening (which might cause loosening) or over-tightening (which can damage parts or cause fastener failure).
How often should a torque wrench be calibrated?
Most manufacturers recommend calibrating a torque wrench every 5,000 cycles or once a year, depending on use. However, higher precision situations may necessitate more frequent calibration.
How do I know if my torque wrench needs calibration?
If you detect inconsistent readings or physical damage, or if the wrench is dropped, it may need to be recalibrated. Regular use in high-demand applications necessitates periodic monitoring.
If you have any additional queries, please do not hesitate to contact us at 01358 726719 or by email at
admin@toolden.co.uk.