Torque wrenches - types, purpose, how to choose

A torque wrench is a hand-held tool for checking the tightening of threaded connections. In plumbing, you can come across a different name for the key - "tared". This word is used as a synonym for masters in research institutes. In some Internet resources, and in old technical literature, you can find the differences between the keys:

• The torque tool is adjusted to a certain tightening torque and cuts off the load when the limit is reached.
• The torque wrench performs all the above functions and shows the current tightening torque on an analog or digital display.

 

But all these concepts have been simplified by manufacturers so as not to mislead buyers. There are standard torque wrenches, scale wrenches and with additional functionality.

 

Why do you need torque wrenches

 

In simple terms, the torque tool is needed in order not to break the thread on the fasteners. Nuts, bolts, screws, through and blind holes in structures have their own tightening limit. When the maximum stop is reached, and the tightening torque is unceasing, the components of the threaded connection can be sheared along the thread groove anywhere. Alternatively, the overtightened fastener element, usually a screw or bolt, is sheared off at the base of the rod in the head area.

The essence is clear, the task of torque wrenches is to tighten the fasteners within acceptable limits. For this, manufacturers of parts, hardware and other products, offer technical specifications for their products. Where all the requirements regarding the tightening force are clearly stated. These standards are issued separately for each type of material. For hardware, the type and composition of the metal, its heat and chemical treatment, tempering, coating, and so on are taken into account.

 

Where are torque wrenches used

 

Hand tools are in demand in the car service, light and heavy industry, construction and the energy sector. Wrenches with dynamometers have no exact purpose. Literally in any field of activity there are requirements for the tightening accuracy of fasteners. It's just that not all specialized specialists follow the recommendations of the manufacturers. In the same car service, when carrying out tire work, you need to tighten the wheels with a torque wrench. It's just that not everyone does it based on their own work experience.

Torque wrenches are actively used in mechanical engineering and the furniture industry, where hardware is often combined with a wooden or plastic base. In such cases, exceeding the torque for the nut, bolt or screw will easily damage the base. And if you do not hold out, then the structure will loosen and fall apart. And in such cases, a torque tool comes to the rescue.

 

What are the torque wrenches

 

The world market is rich in offers, but the types of hand tools do not shine with abundance. All wrenches and dynamometers can be divided into 2 basic categories:

• Limit keys. The tool has a simple mechanism where you can set the tightening limit on a special scale. It is located on the head of the key or in the handle. When the set moment is reached, a click is heard (the sound resembles a breaking of a guitar string). Limit keys can have several settings for ease of use.
• Scale keys. Analog (pointer) or digital (with LCD) wrench, during tightening, shows the current torque. This is convenient for frequent work with the tool, where you have to work with different fasteners and very often. Such a key belongs to the category of a measuring tool, as it provides additional information to the locksmith.

 

The functionality of torque wrenches is expanded with rotation switches and dynamometer settings for specific tasks. The tool may differ in the size of the landing square. The peculiarity is that the benefits of the tool are zero if interchangeable sockets are not available. Accordingly, the key is matched to the available attachments. Or, it is purchased complete with these same heads.

There is one point that the buyer needs to pay attention to. There are no universal torque wrenches. All keys have their own minimum and maximum limits. For example, for precision work, a wrench with a limit of 0-25 Nm is used. And trucks are serviced at service stations with a tool of 300-1500 Nm.

 

Which torque wrenches are better to buy - brand, country of origin

 

The peculiarity of all hand tools is that they are mostly produced in the territories of China or Taiwan. There are exceptions in the form of American, British or German solutions, but their total market share does not exceed 1%.

Chinese and Taiwanese factories can belong to both local brands and European (Asian, American). Each brand has its own policy for the manufacture and sale of hand tools:

 

• High quality. Certificates do not matter. The tool is aimed at tough operating conditions. Keys are designed for inept handling and excessive loads. Such a tool is produced by the brands King Tony, JONNESWAY, Ega Master, Gedore.
• The minimum price of the instrument. The low cost is based on the fact that all torque wrenches are manufactured to specifications. The tool must be used for its intended purpose and in accordance with the declared technical characteristics. For example, if the load is exceeded or improperly used, the tool will break. This includes all Chinese brands whose products can be found in the budget segment. The tool is made with high quality, but you need to work with it carefully.