Choosing a torque wrench: types, characteristics and features

Recommendation points

• Types of torque wrenches
• Torque wrench device
• Types of bits used in torque wrenches

The article discusses various types of torque wrenches, compares their characteristics and cost. In addition, the device and the principle of operation of such keys are described, the possibility of using additional attachments and multipliers is considered..

A torque wrench is a tool that is indispensable in cases where you need to know how well the threaded connection is tightened, which allows you to exclude:

• loose connection of nodes;
• thread stripping;
• mechanical breakage of bolts;
• twisting and cracking of tubes;
• pinching and breakage of engravers.

Each product, depending on what material it is made of, has a tensile strength, according to which the maximum tightening force is limited. You can find out this threshold from the passport data of the equipment indicating the maximum or recommended tightening force, and then set the required actuation value on the key.

The torque wrench is used for the following work:

1. Tightening of threaded and bolted connections in electrical installations.
2. Works with a car engine, chassis.
3. Tightening threaded connections of water and gas hoses.
4. Connection of union nuts in transitions between copper or plastic conduits.

Types of torque wrenches

All torque wrenches can be divided into several categories based on the way they are indicated and adjusted..

1. Torque wrenches with a preset torque, not adjustable.

Hazet 50-200 Nm

These keys are configured to work with a certain effort and cannot be rebuilt by the user. This is their advantage and disadvantage at the same time, since this key is highly reliable, but at the same time highly specialized.

2. Torque wrenches with pre-set tightening torque.

Force 5-25

These keys are simple and reliable, which makes them widespread. By adjusting the spring force, these wrenches can be adjusted to operate at the required tightening torque. The actuation is accompanied by a specific click and a short free movement of the key handle. These keys can be used to work with various extension cords and swivel keys in places where it is impossible to see the indication.

Most models are equipped with a ratchet head or a set of openings as standard.

3. Torque wrenches with pointer indication of the generated force.

Torqueleader CDS 400 S

Thanks to the dial gauge, the device can be used to tighten various connections with unequal permissible torque without readjustment. Such a wrench may turn out to be inconvenient if it is necessary to tighten the connections in places that do not provide free access to them, since the arrow indication may not be visible during operation.

4. Torque wrenches with digital indication of the generated force.

TOHNICHI CPT50X12D-G

Allows you to accurately control the tightening force of the elements (up to tenths, and even hundredths of Nm), which is especially important when installing electronics and performing repair of automotive components.

5. Combined torque wrenches with adjustable tightening torque and dial or digital indication of the applied force.

Effectively protects against accidental application of excessive torque in combination with the ability to continuously monitor the magnitude of the applied force on the indicator.

According to their external shape, torque wrenches can be divided into the following types:

1. Torque screwdriver wrenches, used to work with electronics and various fragile mechanisms.

• Hand torque wrenches. Can be of various shapes and working limits, are most common in both household and production.

Matrix 1/2 “28-210 H / m

3. Industrial torque wrenches. Designed for use on automated conveyors, large repair and production sites.

Torque Wrench Comparison Chart

Torque wrench device

Depending on the specifics of the application and the manufacturer, the device of the torque wrench may differ slightly, but at the same time it will contain nodes common to all types of keys.

1. Removable nozzle (ratchet).
2. Nozzle retaining pin.
3. Spring case.
4. Measuring scale.
5. Adjusting knob.
6. Clamp of the set actuation force.

Types of bits used in torque wrenches

Various types of bits can be used with the torque wrench.

Nozzles: 1 – horn; 2 – cap; 3 – head with a ratchet; 4 – radius; 5 – special form; 6 – slip-on with a cut

The most convenient and demanded are ratchet heads. This mechanism allows you to speed up the wrapping process, it effectively mates with multipliers and sets of socket heads. Due to the possibility of reversing the mechanism, the torque wrench can be used not only for tightening, but also for unscrewing threaded connections.

If it is necessary to apply a significant tightening or untwisting force to the twisted nodes, multipliers can be used in conjunction with a torque wrench. This device is inherently a gearbox that allows you to increase the tightening force transmitted to the mechanism.

Multiplier Handtorque HT3

Comparison of different multipliers

In the market of torque wrenches and various accessories to them, manufacturers from Germany and Japan occupy leading positions. Keys made by well-known brands are characterized by high torque measurement accuracy and reliability, but at the same time, their cost is unreasonably high..

Chinese and Taiwanese manufacturers produce fairly high-quality products at quite democratic prices, which are worth paying attention to both amateurs and professionals..

To work with the electronics, torque wrenches with a working range of 0.1 to 10 Nm are required. In power electronics, for working with cars, plumbing and heating, a key with an operating range of 20 to 120 Nm is useful, this range covers most of the work carried out.

So a hand held torque wrench with a pre-set torque can be a useful addition to a plumber’s, auto-fitter’s and professional electrician’s toolbox, replacing your regular ratchet wrench..