How does a torque wrench

Torque wrench in appearance resembles a regular ratchet, equipped with special scale intended for determining the desired force transmitted to the threaded connection. Depending on the type of the instrument scale may look like a dial gauge, but can also be supplied with a digital indicator screen.

In its most common form, the instrument has a scale embossed on the key; an indicator of the achieved effort in this case will be a "click". This torque wrench has a handle, rotatable, and two scales, where it is applied the number of divisions. The main scale is located on the fixed part of the tool, and support – on a rotating arm.

Usually the torque wrench has a strictly limited range of permissible effort that is specified in the technical documentation or in the instructions to the device. The width of the range can be defined by the limit marks on the main scale of the instrument.
Choosing a key for a car service in advance to find out what efforts might be needed when tightening the threaded connections on separate units.

How to use a torque wrench

Let's say that you want to tighten the threaded connection with a certain force. First you need to select a key with appropriate range. On the base of the tool is screwed the movable arm. She will move to a fixed scale tool. When the arm nearly reaches the desired mark on the main scale, you should switch the attention to scale and rotate the auxiliary handle to the level, exactly corresponding to the desired force. The key is ready to use.

Now to a torque wrench is necessary to attach the end die of the desired size, i.e. corresponding to a nut. Upon subsequent tightening the nut at some point will achieve the effort that will be clear by the distinctive click, which will publish the tool. An experienced master can also feel the onset of moment, change efforts are perceived by the hand.
Click means that the desired tightening force has been achieved, so that the process can be stopped.

If you continue to tighten the threaded connection further, not paying attention to a click torque tool will work like an ordinary key, tightening the nut on and making clicking noises. The key worked for a long time, and the connection has not been spoiled by excessive force, such situations should be avoided. After fully screwing the nuts to the desired position the knob should return to its original position, twisting it back.