Torque Wrenches – Types, Purpose, How to Choose

Torque wrench is a hand tool for controlling the tightening of threaded connection elements. In locksmithing, you may encounter a different name for the wrench – “tarried”. This word is used as a synonym by masters in research institutes. On some internet resources and in old technical literature, distinctions can be found between wrenches:

• A torque tool is adjusted to a specific tightening torque and cuts off the load when the limit is reached.
• A tarried wrench performs all the functions mentioned above and displays the current tightening torque on an analog or digital display.

But all these concepts have been simplified by manufacturers to avoid confusing buyers. There are regular torque wrenches, scale-based, and with additional functionality.

Why are torque wrenches needed

If we speak simply, a torque tool is needed to prevent damaging the thread on fastening elements. Nuts, bolts, screws, through and blind holes in structures have their tightening limits. When the maximum stop is reached, and the tightening effort continues, the threaded connection components can be sheared off along the thread groove anywhere. Alternatively, overtightened fasteners, usually screws or bolts, will shear at the base of the shank near the head.

The essence is clear: the task of torque wrenches is to tighten fasteners within permissible limits. For this, manufacturers of parts, fasteners, and other products specify technical conditions for their products. These clearly outline all requirements related to tightening effort. These standards are issued separately for each material type. For fasteners, the type and composition of metal, heat and chemical treatment, tempering, coating, and so on are considered.

Where are torque wrenches used

Hand tools are in demand in auto repair, light and heavy industry, construction, and the energy sector. There is no specific purpose for torque wrenches. Virtually in any field, there are requirements for the accuracy of tightening fasteners. Not all specialists follow manufacturer recommendations. For example, in auto repair, when performing tire mounting, a torque wrench must be used to tighten the wheels. Not everyone does this, relying on their own experience.

Torque Wrenches are actively used in machine building and furniture industries, where fasteners are often combined with wooden or plastic bases. In such cases, exceeding the torque for a nut, bolt, or screw can easily damage the base. And if not tightened enough, the structure will wobble and fall apart. In such cases, torque tools come to the rescue.

What types of torque wrenches are available

The global market offers many options, but the variety of hand tools is limited. All wrenches and torque meters can be divided into 2 basic categories:

• Limit wrenches. The tool has a simple mechanism where you can set a torque limit on a special scale. It is located on the head of the wrench or in the handle. When the set torque is reached, a click sounds (similar to the breaking of a guitar string). Limit wrenches can have several settings for convenience.
• Scale wrenches. An analog (pointer) or digital (with LCD screen) wrench shows the current torque during tightening. This is convenient for frequent work with the tool, where different fasteners are involved and very often. Such a wrench belongs to measuring tools as it provides additional information to the locksmith.

The functionality of torque wrenches is expanded with rotation switches and torque adjustments for specific tasks. The tool may differ in the size of the square drive. The key point is that the tool is useless without interchangeable socket heads. Therefore, the wrench is selected based on the available attachments or purchased as a set with these heads.

One important point for buyers: there are no universal torque wrenches. All wrenches have their minimum and maximum limits. For example, a precision work wrench has a limit of 0-25 Nm. And trucks are serviced at maintenance stations with tools of 300-1500 Nm.

Which torque wrenches are better to buy – brand, country of manufacture

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

Chinese and Taiwanese factories may belong to local brands or European (Asian, American) ones. Each brand has its own policy regarding the manufacturing and sale of hand tools:

• High quality. Certificates do not matter. The tool is designed for harsh operating conditions. Wrenches are rated for rough handling and overloads. Such tools are produced by brands like King Tony, JONNESWAY, Ega Master, Gedore.
• Minimum price. The low cost is based on the fact that all torque wrenches are manufactured according to technical specifications. The tool must be used as intended and in accordance with the declared technical characteristics. For example, exceeding the load or improper operation will break the tool. This includes all Chinese brands, products that can be found in the budget segment. The tool is made well, but it must be used carefully.