The correct torque is crucial for the proper assembly and operation of bolted components in various structures and mechanisms. In such cases, you can't rely on your own intuition; instead, you must use appropriate tools with a maximum tightening force limit. But how do you set the correct Nm value on a torque wrench and how do you calibrate it?
A torque wrench is a tool that allows for precise tightening of screws with a specific amount of force. Inside, a spring tightens to the preset torque. Once the torque is reached, the mechanism locks further tightening and indicates this with a click, for example. Are torque wrenches dial or digital? There are several types of wrenches available on the market, each with a different operating mechanism:
pointer – they have a scale and a pointer showing the current moment.
mechanical (click) – the most popular, they signal the achievement of torque with a sound.
electronic – LCD display shows the moment, remembers the last settings.
broken – the key hinge stops working when the torque is reached.
Correct wrench use involves selecting the Nm range for the components being connected and precisely setting the value. The wrench should be held by the handle, tightening the screw evenly. After completing the job, set the minimum value and store it in a box. What does Nm mean on a torque wrench, and how important is torque? Nm (Newton meters) is a unit of torque. The higher the value, the more force is applied to the screw. Too low a value can cause the connection to loosen, while too high a value can damage it.
Using a torque wrench prevents assembly errors . This is especially important for car wheels, engine connections, and other applications where tightness or performance are critical. A typical torque value is 110–140 Nm. Set the value on the handle scale, lock the mechanism, and tighten the bolts until you hear a click. For engines, use wrenches with a range of 20–40 Nm or dedicated torque settings. A precise tightening and adjustment sequence ensures tightness and prevents failures.
The choice of key depends on the task:
40–200 Nm – for wheels and suspension
up to 30 Nm – to the engine
up to 25 Nm – to light
up to 0.5 Nm – for valves and precision components
The best accuracy is achieved in the middle of the scale range.
Calibration checks the accuracy of the readings. It's recommended to do this annually or after 5,000 uses. It's best to have it performed by a professional service center or use a specialized measuring device. Learn more about torque wrenches in our automotive store. Also check out:
