5 Reasons Your Torque Wrench Needs Regular Calibration

Whether you’re using a torque wrench on the job or in a home garage, accuracy matters. The entire purpose of a torque wrench is to apply a precise amount of force — and if that value is off, even slightly, it can lead to failed fasteners, damaged components, or serious safety risks.

You might assume that purchasing a high-quality, name-brand torque wrench guarantees long-term accuracy. While quality absolutely matters, no torque wrench stays perfectly accurate forever. The only way to be confident in your tool’s performance is through regular calibration. Below are five key reasons why torque wrench calibration is essential.

Accuracy Requirements

Manufacturers specify an expected accuracy range for each torque wrench, but that specification only applies if the tool is properly maintained. Over time, wear and normal use can cause drift, making it impossible to know whether your wrench is still producing repeatable, accurate results.

Torque wrench accuracy can range anywhere from ±6% to ±1%, with higher-accuracy tools typically costing more. If your application requires tight torque tolerances, investing in a premium wrench is recommended. However, even high-end tools must be calibrated regularly to establish a reliable performance history.

Lower-cost or economy models often require more frequent calibration due to lower-quality internal components. To meet industry best practices, torque wrench calibration should follow internationally recognized standards such as ASTM E2624, published by ASTM International.

Frequency of Use

According to ISO 6789, torque wrenches should be recalibrated every 5,000 uses or every 12 months — whichever comes first. This is considered a minimum guideline and should never override your process accuracy requirements.

In many professional environments, recalibration every 2,500–3,000 uses is more common. Simply put, the more frequently a torque wrench is used, the more often it should be calibrated to ensure consistent and reliable performance.

Improper Storage

Proper storage plays a major role in maintaining torque wrench accuracy. Adjustable torque wrenches should always be stored at their lowest marked setting, not at a higher torque value and not dialed all the way down to zero.

When stored above the lowest setting (typically around 20% of maximum torque), the internal tension spring remains under load. Over time, this weakens the spring and causes the wrench to under-torque across its entire range. On the other hand, backing the wrench down to zero can allow internal components to shift, also affecting accuracy.

If a torque wrench has been improperly stored for extended periods, professional recalibration is necessary. In some cases, the tool may no longer be adjustable within manufacturer specifications and may need to be replaced.

Temperature and Environmental Exposure

Using or storing a torque wrench in extreme temperatures — below freezing or above 120°F — can lead to condensation inside the tool, increasing the risk of internal rust. Exposure to rain, snow, or other harsh environmental conditions can accelerate corrosion even further.

High temperatures can also cause internal lubricants to thin or seep, which negatively impacts performance. Rust, lubrication issues, and environmental damage all compromise accuracy and shorten the life of the tool, making recalibration essential.

Improper Use

Torque wrenches are precision instruments and must be used correctly to maintain accuracy. Applying force anywhere other than the handle grip, using cheater bars or pipes, or using a torque wrench as a breaker bar can overload internal components.

ISO 6789 requires recalibration if a torque wrench has been overloaded by more than 25%. Accidental drops are another major concern — a single drop can affect torque accuracy by as much as 30%.

Determining the frequency of calibration for your torque wrench may be mandated by your specific industry or it could be a personal decision based on one or many of the factors above. Regardless, finding a trusted torque wrench calibration service provider is vital to verifying your instrument’s readings and making any necessary adjustments to bring your torque wrench back into manufacturer’s specifications. Precision Calibration Systems is ISO 17025 accredited for torque wrench calibration up to 1100 foot pounds. With our standard 24-48 hour turnaround time, your torque wrench can be quickly and accurately calibrated regardless of your location. For more information, contact us today.