Torque wrench for a car: types and review of the best

Types of torque wrenches

There are three categories in total: torsion, click, indicator.

A torsion wrench uses a handle with a scale and a fixed pointer. The error can reach one fifth. This key works in both directions. The advantages include ease of use and low, relative to other types, cost.

The disadvantages are low accuracy, which decreases as the key wears out, and inconvenience of use in hard-to-reach places where it is difficult to follow the scale. The torsion wrench cannot be adjusted. If it has lost its accuracy, the tool must be replaced.

The limit or click torque wrench must be pre-set at the moment of operation. There are models that work in both directions. The force that this tool applies can range from half a kilogram to one hundred and fifty kilograms. The maximum error does not exceed one tenth. This type of key is the most common due to its ease of use and low cost. After use, it is necessary to return the tool to the zero state, otherwise its accuracy may decrease.

To achieve maximum accuracy and minimal wear, you do not need to use the key at maximum values. This will help extend its service life. When a click is made in the handle, the key has reached the set torque. This greatly simplifies the work: you need to set the required torque and tighten the fasteners.

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Thanks to this technology, work progresses faster, and because you don’t need to follow the arrow, the tool gives an audible warning, making it convenient to use in hard-to-reach places.

An indicator torque tool allows you to monitor the dynamics of fastening of fasteners. The design of the instrument is equipped with a scale with one or two arrows. One is set to the required value of the moment of force, the other records the current moment. When tightening is complete, the arrows should be aligned.

The indicator key works in both directions. The error of this type of key does not exceed one hundredth, and it can be adjusted to different units of measurement. When the required tightening torque is reached, the key will notify you with a light and sound indication.

How to use a torque wrench

From an application point of view, a torque wrench is no different from a conventional tool. It is designed to perform the same functions, only with an increased degree of control and precision of the force generated. When using torque wrenches, you should begin by carefully reading the user manual. It should be remembered that the instrument belongs to the group of precision devices and does not tolerate negligence or careless handling. Each type of key design has its own requirements for operation, so a preliminary familiarization with the features of the tool will help keep it intact and get the desired result. Regardless of the design, there are general rules for using torque wrenches:

• Keys should be stored with zero torque. This means that after completing the work, it is necessary to set the tool scale to zero force and completely loosen the adjustment mechanism.
• You should not attempt to set values ​​outside the key's range.
• Cleaning the tool should be gentle, not allowing the factory grease to be removed from the force setting mechanism. It is recommended to only wipe it.
• Do not rotate the handle while the lock nut is tightened; this will cause the tool to break.
• Particular attention should be paid when operating at low torques.
• After long-term storage, it is not recommended to immediately set large values; first, you should work a little with little effort.
• It is not allowed to use pieces of pipe to enhance the moment, only standard devices.
• It is prohibited to use keys for purposes other than their intended purpose, or to use them instead of a lever or a hammer.

Important! There is some difference between the wrench reading and the final force on the fastener due to friction.

Let's look at the features of using different types of keys:

How to use an electronic instrument

Electronic keys are used for the most critical and precise work. They have the ability to save settings, which can significantly save time. This allows you to switch device settings with one click of a button. At the same time, it is not always possible to control the indicator readings, so the work conditions should be taken into account in order to avoid complications. The tightening force is controlled by the operator in real time, and torque amplifiers can be used for enhanced capabilities.

You can save settings in electronic keys

Switch

Keys with arrow indication are used to work with mechanisms of medium responsibility. The tightening force is monitored visually and the operator must ensure that it does not exceed the permissible value. Optimal operating conditions are:

• Good lighting.
• Availability of connecting elements, allowing high-quality control of indicator readings.

Lack of conditions may cause the permissible force to be exceeded and the fastener to fail.

It is recommended to use this key only in good lighting conditions.

Using open-end wrenches

Open-end torque wrenches are used when connections are accessible and prevent the bit from slipping off the bolt head or nut. It is not recommended to use such wrenches at high torques, when excessive force can tear the attachment from the fastener. The dimensions of the nozzles and fasteners must correspond exactly to each other so as not to cause the horns to rip open, changing the dimensions and rendering the nozzle inoperable.

The dimensions of the key and fasteners must strictly correspond

Click type

Click-type wrenches allow you to control force in tactile ways. This is convenient when working in conditions of poor visibility and complex mechanism configurations. Tighten only until it clicks; you should not continue rotating after it. Particular attention should be paid to weak forces, when the click may sound earlier than the operator expects.

The maximum force is adjusted by combining the data on the scale of the handle and the key lever. The main scale provides coarse adjustment in steps of 5 Nm, and the additional scale provides fine adjustment within 5 Nm to obtain the exact required value.

It should be taken into account that even key samples of the same type may have their own requirements and operating features, so you cannot use the tool without studying the technical description or instructions. The calibration interval must also be maintained to ensure accurate torque indication.

You need to tighten the fasteners until the key mechanism clicks.

How to determine the tightening torque (with table)

The optimal torque for this connection is indicated in the passport or instructions for the mechanism. At the same time, such information is not given for all connections, but only for the most important and responsible ones. In some cases, the permissible values ​​are not indicated at all, which creates the possibility of destruction of the fastener with unpleasant consequences. There is a special table to determine the maximum or optimal values ​​of the applied force. Below is a table with nominal values ​​and limit values.

Correctly, the torque of the connections should be indicated in the technical document

Using this table, you can determine the maximum bolt tightening parameter

Using these tables will help you select the desired fastener tightening mode and independently determine the strength limits of individual components or connections. The given values ​​are valid only for fasteners, the impact on the mechanism elements is not taken into account.

There are extensions (amplifiers) for torque wrenches. They increase the length of the lever, allowing you to change the range of the tool and obtain more torque on the fastener. This is convenient for the user, allowing you to use one key without purchasing several different sizes. When using extension attachments, the instrument scale readings have to be recalculated, since the magnitude of the applied torque changes.

Torque wrench extensions help achieve greater bolt torque

The use of extension cords that do not comply with the design of the key is prohibited.

What is the best torque wrench for a car?

For high-quality car repairs, it is necessary to use tools that guarantee the proper strength of the threaded connections. When a master has a lot of experience, he works by eye, but with this method there is always a human factor, which implies error.

The latter can result in a number of unpleasant consequences. From breaking a wheel stud to damaging vital vehicle parts. For this reason, professionals use torque wrenches for anyone involved in auto repair.

The type of tool is selected depending on the needs of the master. The most accurate, but also the most expensive, are indicator keys.

The Force key received the largest number of positive reviews. It operates over a very wide range, up to 350 Nm, and has a maximum error of no more than three hundredths. In addition, the master will be able to independently choose the direction of rotation. The key is recommended for car service workers and truck owners.

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The cost of a torque wrench starts from five hundred rubles and increases depending on the characteristics and type. When choosing a tool, you need to be guided directly by the scope of work; there is no need to select the maximum power where even one fifth of it is enough.

You can buy a torque wrench at a tool store or have it made to order. In any case, you can ask the seller to provide certificates and ask for help with your choice.

According to reviews, a torque wrench simplifies work and increases vehicle safety. A master who purchases a torque wrench gets the opportunity to tighten the nuts with a large force interval and can work with different squares for the head.

By choosing a tool according to your needs, you can achieve the optimal price-quality ratio and not lose money. In addition, confidence in the strength of the vehicle's structure is worth the money.

How to pick and choose?

Each has many different benefits and amenities to consider before making a purchase.

Below is a list of parameters that you need to rely on when choosing.

• Torque range;
• Connection size;
• and a method of notifying that the required effort has been achieved;
• and units of measurement;
• Material of manufacture;
• Size ;
• Availability of a case;
• Convenience of setting torque and reading the scale;
• Handle material;
• Warranty, service center and availability of spare parts;
• Directions of action;
• Availability ;
• Reset button;
• Articulated head;
• Country of Origin;
• Price.

Having listed all the parameters that need to be paid attention to, we will try to talk in more detail about each point in order to decide which one in a particular case to solve the problem.

Torque range

This parameter determines the range in which it works. The range of a tool is closely related to the meaning that needs to be conveyed in any given use.

in total they operate within 25-85% of the main range.

For example, it is necessary to tighten a threaded connection with a force of 30 N/m. with ranges of 6-30 N/m 16022030 and 20-110 N/m 16033110 can cope with the task. So what is 16033110 with a range of 20-110 N/m, since the required force “does not lie” at the extreme value of the scale, which means that the tool spring will not stretch so quickly. Yes, the second one, unlike the first one, will not be able to work with smaller values, but for less effort you can purchase a second one, for example, with a range of 5-25 N/m 16032025.

Therefore, do not select an instrument that will primarily be used at the lower or upper end of the scale. You might be tempted to do this to save money, but the torque output could seriously outweigh any savings.

Connection square size

Have you ever purchased a tool regardless of the size of the attachment? Choose according to the size of the inch assembly tool (sockets, extensions, etc.) that you most often use (1/4, 3/8, 1/2, 3/4 or 1 inch). In some cases, adapters may be required.

They also exist with specific drive sizes: 9x12mm and 12x14mm. These are used together. Open-end wrenches allow you to tighten fasteners between the parts being connected, and are also capable of working with nuts on high studs. Torque wrenches for air conditioners are an example of using such a tool. Therefore, the choice directly depends on the specifics of the work performed.

and a method of notifying that the required effort has been achieved

There are many models from which you can choose. Here are the main ones:

• Switch;
• Snap;
• Digital;

The first type is more used by amateurs or in garage workshops, where the high ones are not regulated, and are the least accurate of all. The force must be controlled by an indicator at a specific point in time, which is not very convenient, since it is always necessary to monitor. The start of the controlled range of the torque wrench from 0 Nm is another feature of these models.

used in most professional workshops because it uses to indicate when the required preset torque has been reached.

However, some people prefer electronic torque wrenches because the display can track the force being applied at a specific point in time. Also, when the set torque is reached, it emits a sound signal that sounds louder than.

and units of measurement

Different models have different torque transmission. The most important are the models, then and only then.

supplied with a factory calibration certificate indicating the date and . Therefore, the tool should be calibrated according to the maintenance schedule to maintain factory specifications. Verification must be carried out annually or more often, depending on the frequency of use.

The instrument may have scales with multiple torque measurement values. Before purchasing, be sure to look at what values ​​are used for measurement in your area so that you do not need to convert to the required values. Basic torque values:

• N/m (Newton per meter);
• Kg/m (Kilogram per meter);
• lbf/ft (Foot-pounds).

Unit conversion:

• 1 Kg/m ~ 10 N/m;
• 1 kg/m ~ 7.2 lbf/ft.

Material of manufacture

Most are made of metal with plastic or rubber parts/inserts. The more plastic a tool contains, the more carefully it should be used and stored. As a rule, plastic is located in the handle area, increasing the convenience and ergonomics of use.

Size

Take this into account if you need to carry out work in hard-to-reach places. At the same time, you need to understand that the higher the torque range, the larger and longer the tool will be.

Availability of a case

It is worth choosing a measuring device, so it is necessary to exclude the possibility of falling, moisture and other possible factors of damage.

It is necessary to store only with the minimum torque set to avoid stretching the spring and to preserve the tool.

Easy to set torque and read scale

The tool may have different dials for setting or controlling torque.

If the model has, then the scales should be easy to read and the torque should be easy to set.

The scale should also be clearly visible and have a minimum value for dividing torque values ​​in order to achieve maximum torque transfer when transferring force to the fastener.

It can be set at the required moment using the buttons. Make sure the display has a backlight, which will allow you to work with the tool in dimly lit areas.

Handle material

Handles can be made of different materials and have different design features. As a rule, the handle is made of metal or plastic or rubber. There are ergonomic handles that have a special shape for the girth.

Remember that during use the tool may become dirty with any liquids, so it must have a handle that will not slip in your hands. For example, the metal handle has a special notch, and plastic and rubber handles are made with the addition of oil and petrol resistant materials.

In any case, to feel the comfort of the handle of this or that, you need to hold it in your hands.

Warranty, service center and availability of spare parts

The tool must have a warranty period, which is established by the manufacturer. To count on a warranty, you need to understand that it must be used strictly for its intended purpose in compliance with all operating requirements.

Check the warranty period of use and the availability of spare parts, first of all, repair kits for the ratchet mechanism. Pay attention to the presence of a service center, since a serious and responsible company not only sells, but also services torque tools.

Ratchet repair kits are available for most AIST and MASTER brand models. AIST also has its own service center, which provides repairs and maintenance, both warranty and post-warranty.

Do not use the tool as a tool for unscrewing fasteners. Use together with amplifiers, such as a trumpet, is strictly prohibited. Do not throw away the tool after work.

In addition to the warranty, models must have a factory verification, which indicates the date, where and by whom it was produced.

Directions for action

Most can transfer torque to fasteners that have . Therefore, if, due to the specifics of the work, it is necessary to tighten a threaded connection with, then it is worth buying models that can work like with, but these are more expensive.

Presence of a ratchet

The mechanism allows you to quickly tighten the fastener, since there is no need to rearrange the tool when tightening. If models have this feature, then they are deprived of this option.

Reset button

Some have a reset button for bench tools, such as socket sockets. This option allows you to quickly remove the attachment from the .

Articulating head

Allows you to work with the tool in hard-to-reach places. The head has a hinge that allows you to bend the tool in the desired position.

Country of Origin

Most brands presented on the Russian market are produced in factories in China and Taiwan. AIST

and
MASTER
are manufactured and tested on modern high-tech production lines of factories in Taiwan. How do those made in Taiwan differ from their counterparts in mainland China? Taiwanese keys have:

• A clear
  scale for setting the required torque;
• A characteristic loud
  signal when the set force has been achieved;
• Reliable
  spring and ratchet mechanism;
• Long
  service life.

Price

In many ways, it can play the highest role in the selection process. Once you've narrowed down your options based on the criteria above, you can worry about costs.

At the same time, you can simply choose the cheapest option, but you need to carefully weigh the other offers, as you may find that other options ultimately lead to a better purchase overall.

How to choose a torque wrench

1. The quality of repair directly depends on the correctly selected tool. The main parameters of torque wrenches are torque and square.
2. The maximum force must be specified in Newton meters. Typically the tool has a range of this value. For a truck owner, a wider range is needed, and to perform small jobs, therefore, narrower.
3. Square is measured in inches. It is defined to set the size of the nuts used. Typically, the size of the square and the maximum force are related. For minimum torque, squares no larger than a quarter inch are used.
4. In order for the tool to serve for the longest possible period and be more accurate, you need to be guided by the required force. It should be approximately in the middle of the key range.

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How to check the key

After completing the work, it is necessary to put the key in the zero force position. Otherwise, it will negatively affect its accuracy and power range. If, however, the instrument has spent some time in this condition, you can check it by taking it to the nearest workshop. If you don’t want to turn to professionals, you can always check the tool without leaving home.

For example, let’s take a key of the already known Force brand with a range of 5-25 Newton meters. The first thing to check is the accuracy of the scale. After successful testing of the scales, you need to begin control tests. You will need a size 8 bolt and two nuts. One screws up to the bolt head, the other a little.

It is necessary to clamp it in a vice and tighten the bolt as much as possible. That is, a force exceeding the range of the tool being tested. Any torque value can be set on the key, and it is smoothly pulled to the selected location on the collar until it operates. The force that acts on the key must be perpendicular to the tool collar. An important role is played by the reading of the scales and the distance from the center of the key head to the place on the driver to which the force was applied.

The steps must be repeated several times, for different tightening torques, and write down the values.

Then check using the formula in which the required tightening torque is equal to the product of the steelyard reading, arm length and free fall acceleration. The results of the formula are compared with the set torques on the key. If the error does not exceed that specified by the manufacturer, the instrument is in perfect order.

Installing Adjustable Torque Wrench Scales

At the end of the handle, a special clamp is untwisted, which allows you to set the required torque value on the scales of the limit torque wrench. Having set the required value, the lock must be screwed back. The adjustable torque limit wrench is now ready for use. When the set torque is reached, the limit torque wrench will click and will not allow the set value to be exceeded, slipping and making characteristic clicks. After work, the scale indicators must be returned to their original position, i.e. to zero, so that the key spring does not stretch or weaken. If you do not do this and leave the adjustable torque wrench in the working position, this will lead to a loss of measurement accuracy and threaten the instrument’s incorrect operation.