Torque wrenches—and the people who use them to build and maintain planes—are unsung heroes of the skies.

Torque wrenches measure the force that causes an object to rotate. Aircraft mechanics use torque wrenches to ensure that bolts and fasteners on planes are correctly tightened. Without them, a plane could come apart in midflight.

But like any measurement tool, torque wrenches need to be calibrated regularly to make sure they’re giving accurate readings. If these measurements are off, the results could be disastrous.

Calibrating these tools is expensive and time-consuming. That’s because these calibrations are typically done on a large device in a lab, not onsite where airplanes are being maintained. So that requires shipping the wrenches to the lab and then waiting for them to be calibrated and returned.

Thanks to advances in measurement science at NIST, calibrations may soon be performed locally instead. And it all started with... Lego bricks?

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