How Often Should a Torque Wrench Be Calibrated?

How often should a torque wrench be calibrated?

Last updated 9 October 2026

Short answer

Most torque wrenches should be calibrated at least every 12 months or after about 5,000 uses, whichever comes first, and straight away if the wrench is dropped, overloaded or gives results you doubt. Heavily used wrenches, or wrenches used on safety-critical joints, are often checked more often.

A torque wrench only protects you if it applies the torque it claims to. Springs relax, mechanisms wear and wrenches get knocked around, so accuracy slowly drifts. Regular calibration finds that drift before it causes an under-tightened or over-tightened fastener.

The common rule of thumb

The international standard for hand torque tools, ISO 6789, is widely applied with a default recalibration interval of 12 months or 5,000 cycles, whichever comes first. Your own quality procedures, customer requirements or the manufacturer’s instructions may set a different interval, and those take priority.

What can shorten the interval

Heavy use. A wrench used all day on a production line reaches 5,000 uses far sooner than one in a tool crib.
Safety-critical work. Aviation, rail, lifting equipment and pressure systems often require tighter control, so intervals of 6 months or less are common.
Harsh environments. Dust, moisture, heat and chemicals all accelerate wear.
Poor storage or handling. Click-type wrenches should be stored according to the manufacturer’s guidance, usually at the lowest setting.

Calibrate sooner if…

the wrench has been dropped or knocked hard;
it has been used above its rated maximum;
the click feels different, or readings disagree with another wrench;
it has been repaired or adjusted;
a fastener has failed and you need to rule out the tool.

What a calibration involves

The wrench is tested against a reference torque standard at several points across its range, and the results are recorded against the tolerance for that wrench. Where the wrench is out of tolerance it can usually be adjusted and re-tested. The calibration certificate then records the results and the traceability of the equipment used.

Keep a simple register

Give each wrench a unique ID, record its last calibration date and the date the next one is due, and remove it from use when it is overdue. A register makes audits straightforward and prevents out-of-date wrenches being used by mistake.

Frequently asked questions

Does a torque wrench need calibrating if it is rarely used?

Yes. Many procedures set the interval by time as well as by use, because springs and mechanisms can drift even when a wrench sits in storage. Follow your procedure and the manufacturer’s guidance.

Can torque wrenches be calibrated on site?

Often, yes. Many wrenches can be checked on site with a portable torque tester, while others are better tested in a laboratory. The right option depends on the wrench type, its range and the accuracy you need.

What is the difference between checking and calibrating a torque wrench?

A quick check compares the wrench with a tester or another tool to catch obvious problems. A calibration tests it against a traceable reference standard at defined points and produces a certificate with documented results.

What happens if a torque wrench fails calibration?

If it reads outside tolerance it can usually be adjusted and re-tested. If it cannot be brought back into tolerance it should be repaired or retired, and you should consider whether work done with it since its last good calibration needs to be reviewed.