Torque
This is a very important parameter, here you cannot be mistaken either up or down. If the torque is too low, the wrench may not be able to cope with a difficult fastening or tighten it poorly. If the parameter is too high, the tool can break the thread on the nut and damage the fastening. For simple tasks (household tasks, repairing plastic greenhouses) 160 Nm is enough, and for complex tasks (construction of a structure from rails). over 600 Nm. For simple work at the service station, you can purchase an impact wrench with a torque of 350-500 Nm. this is enough for all basic tasks.
Which wrench is better for car service and tire fitting?
The best impact wrench for a car service is a pneumatic impact wrench with a high torque (600-1600 Nm) and at least 6000 revolutions per minute. Such a tool will be able to cope with all assigned tasks and withstand intensive use.
Power
This characteristic affects the working life and capabilities of the tool. For professional models, the power can reach 1.2 kW. This is enough to unscrew even powerful bolts in a construction crane or remove wheels from a massive truck.
Electric (network) wrenches
In network nutrunners, the source of rotational motion is the electric motor. The rotation is transmitted to the percussion mechanism, which converts the constant rotation into frequent shock impulses that twist or unscrew the fastener. It is worth noting that at a low load on the wrench (less than 10% of the rated torque), impacts may not be generated, and the work will be performed linearly (as in a conventional screwdriver).
A blow in a wrench, unlike a blow in a drill or screwdriver, does not act along the axis of twisting, but along a tangent. This makes it possible not to hammer the fasteners into the material, namely to tighten.
The principle of impact generation in a wrench is quite simple: upon reaching a certain tightening force, the striker slips and accelerates, after which it strikes the “anvil” with great effort. Then the process is repeated. The force of a single blow is small enough, but a large number of them create a high torque.
Electric corded impact wrenches are well suited for applications where an air compressor is not available. Since the compressor required to power even the weakest air impact wrench must have a large air reservoir, the network impact wrench is preferable to use in places where it is not possible to place a large compressor. For field installations, it is also easier to take one power wrench with you than an air wrench and a compressor, which also need electricity to operate. An electric wrench will be enough for periodic maintenance of a passenger car, small agricultural machinery, as well as for the installation of metal structures and wooden frames.
Pneumatic wrenches
Two power blocks are installed inside each pneumatic impact wrench:
- pneumatic motor;
- shock load assembly.
After pressing the start button, compressed air enters the tool through the pneumatic drive (to obtain it, an air compressor is needed). There are two channels inside the wrench. air flows through one of them, rotating the turbine in one direction or another. The direction of the air flow can be changed with a special switch. When choosing, it is worth considering the parameter of air consumption. it should not be more than the compressor produces.
Fasteners are hit by special cams with a complex configuration. If the tightening torque is insufficient, they are tilted back, simultaneously turning, and then “bypass” the engagement. As they rotate, they gain momentum, then hit the obstacle again and the process repeats. This continues until the fastener breaks loose from its place. This principle of action means that you do not have to apply force when working with complex bolts. the wrench will do everything on its own.
Among the main advantages of pneumatic impact wrenches are the following:
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- high strength and resistance to stress;
- small size that allows you to work with the tool in hard-to-reach places;
- low risk of breakage due to the minimum number of parts in the structure;
- safety when working in places with a high level of humidity (there are no electrical parts inside the tool);
- resistance to work in dusty conditions, where conventional electric tools fail when dust or foreign small fractions enter the electric motor.
Pneumatic wrenches are a very good purchase for service stations and tire fitters, since they rarely break down and have a significant resource. If you have an air compressor, you can purchase an air impact wrench for garage work. However, if you rarely need to work, or you do not have an air compressor, it makes sense to consider electric wrenches.
Types of wrenches
Wrenches are divided into several types. pneumatic and electric. The latter, in turn, are subdivided into network and battery. Each type has its own characteristics that will affect the choice of instrument.
Speed
For work in a service station or construction, it is worth choosing a model with a rotation speed of up to 7000 rpm (a pneumatic tool is capable of developing this speed). For home use, even less than 1000 rpm is enough. too high a speed for everyday tasks will be superfluous.
Cordless wrenches
These are power tools, the engine of which does not receive electricity from a stationary network through a wire, but with the help of an autonomous rechargeable battery. Their main advantage is the ability to work in remote and hard-to-reach places where there is no power grid. They are also convenient to use when working with frame structures at a height, since there is no hose or wire to the tool. This is a good option for field work.
When choosing a cordless nutrunner, it is important to pay attention to the battery capacity. it depends on how long it can work without recharging.
Main selection criteria
Most often, such tools are purchased for household needs and self-repairing cars. There are 3 criteria in the first place when choosing a device. It:
Power. The list of tool capabilities also depends on the indicator of the working resource. Professional models can deliver up to 1.2 kW. This value is sufficient even for loosening bolts in a construction crane or fastening wheels on trucks. The larger the resource, the more opportunities the tool provides.
Torque. This parameter is the most important, so the choice must be approached carefully. If selected incorrectly, the tool can tighten the nuts harder than required. As a result, this leads to breakage of keys when on the road it is necessary to replace a certain part and put a new wheel. Too high a value will break the thread. Therefore, this parameter must be taken into account and the tool must be selected based on the required value. For example, if it is required to repair plastic greenhouses, then 160 Nm will be enough, for the construction of a rail structure. 610 and 1000 Nm. The average value of 440 Nm is, for example, DeWalt DW294.
Speed. In modern versions, the value varies within 3000 rpm. This indicator is most appropriate if installation work is carried out at service stations or construction enterprises. For domestic needs, you should choose a tool with a lower value, excess power and number of revolutions are not needed. The best option would be 40-100 rpm.
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The last two parameters are most important for professional tools where human strength is not enough. In this case, you need to choose powerful devices.
Design features and principle of operation
Outwardly, such devices are similar to pistols. The tool is equipped with a handle and a barrel, which consists of working elements and a number of systems. The latter also provides for the location:
- engine;
- springs;
- clamping.
The principle of operation also depends on how the wrench is arranged. When the tool is turned on, the engine is also started, to which energy is supplied. After that, it is fed to the gearbox. The latter, in turn, actuates the clamp. If the model provides for the presence of a second spring, then this option is also suitable for unscrewing threaded connections.
The chucks are available in different bore sizes: 1/2, 3/4 and 1 inch. The first option is relevant to use for solving problems in everyday life, the second and third. in construction and car workshops.
The principle of operation of the instrument is based on physical laws. The hammer strikes the output shaft while simultaneously directing its force onto it. Such movements lead to the formation of a moment of force. The design features of the device contribute to the fact that during operation the user does not feel vibrations. The scheme of operation of an impact wrench is similar to a simple hammer, when it is set in motion, swinging, and when the maximum amplitude value is reached, it is lowered onto an object.
The pneumatic version differs in that it does not require a network connection. Consequently, the operation of the tool is also possible in hard-to-reach places, on sites where there is no outlet. The main advantages are high precision and speed of work. With this option, the solution to the task does not take even 5 minutes. How does a pneumatic impact wrench work? The principle of operation of such an instrument is the same as that of a percussion instrument. The only difference is that the first works in the absence of a network. The torque is also different, the indicator depends on the size of the turbine, the number of blades and the pressure supplied by the compressor.
How to choose the right wrench: 10 main criteria
An impact wrench is a hand tool that is widely used for fixing threaded connections and fasteners. With the help of such an apparatus, wood grouses and anchor screws are installed. The device on the modern market is presented in two versions: pneumatic or electric. The first one works under high air pressure, and its use is relevant for production purposes. For solving everyday problems, the second option would be.
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What is a wrench. now it is clear, it remains to figure out the main parameters of the tool that will help you choose the right model.
Types of devices
Wrenches differ in the type of execution. There are several types of instruments. The first on the list is percussion. This option is considered the most effective in the modern market. What is an Impact Wrench? This is a device that allows you to perform a number of tasks, in particular, tightening and unscrewing screws and other threaded fasteners. In this case, the second option is possible only if there is a reverse.
Striking devices, in comparison with traditional ones, have better performance characteristics, although their cost is much higher. A special torque adjustment system allows you to customize the device for a specific case. The main characteristic of such a tool is the pulse frequency. The average value is approximately 3000 bpm. The introduction of electronic torque control systems provides convenience for the user, guarantees the quality of the task.
It is rational to purchase shockless models if work with large and heavy structures is expected. This is due to the high torque of rotation. Such a device is used for tightening and loosening nuts. The device is also distinguished by the option of reverse, and the handle is shaped like a pistol.
Many are interested in what an impulse wrench is. The operation of such a tool is based on the percussion-rotational principle. As a result, movements are transformed into impulses. They go to the square, to which the socket head is connected directly. Using a special button, the direction of operation of the device is set: twisting or unscrewing.
Appearance of Impulse Wrenches
There are a number of factors to consider before choosing an electric impact wrench. It:
- power;
- speed;
- maximum torque.
Correlation of the tasks ahead with the technical characteristics of the tool will help you choose the right model.
For such an option to function stably, a permanent connection to the AC mains is required. The devices are represented by a wide range of power. At the same time, deviations in the accuracy of displaying a given indicator are insignificant, and the device is different:
- almost complete noiselessness;
- compact dimensions;
- ease;
- built-in power regulator of the torque of rotation;
- a system for establishing the direction of operation.
The torque of rotation of such tools varies in the range of 40-6000 Nm. In this case, the engine is cooled directly during operation, which eliminates the need to take a break.
The pneumatic version of the devices works on a different principle. In other words, compressed air is supplied through a special tube from the compressor. The peculiarity lies in the fact that this type of apparatus does not include an engine in the design. This ensures the lightness of the device, and, consequently, reduces the load for the user during operation. Before choosing a pneumatic impact wrench, you need to understand the scale of the task ahead. The choice of the appropriate model depends on this.
But which impact wrench is better: electric or pneumatic? Each of the options has both advantages and disadvantages. For example, for tire fitting, choose a pneumatic wrench rationally. This is due to the fact that the service station already has a compressor to carry out the work, so you will not have to spend a lot. Such a choice of a wrench for a car service guarantees a high-quality performance of the task. In all other cases, it is more expedient to purchase an electrical option due to the fact that compressors are expensive systems, and a network connection is available for everyone.
Shape, materials and comfort
The shape of the impact wrenches can be straight and angular. In appearance, they resemble a drill. The only difference between them is the lack of a drill in the former. Instead of this working element, an extension nozzle is used, which is needed to fix the nut.
As for the materials used, here preference is given to a metal case, a handle with a rubberized pad. In the latter case, this is necessary to reduce vibration on the working surface and the user’s hand. Rubberized inserts along the entire surface of the case minimize the negative impact as much as possible, providing convenience and reliability. The production of devices is carried out according to innovative technologies:
- the backlight indicator is introduced;
- an electronic rotation control system is used;
- an option is used that guarantees an instant stop of the device.
In order to minimize breakdowns and the formation of various defects, preference should be given to manufacturers who have proven themselves well on the market. Popular manufacturers include:
Bosch. The company offers high-quality impact wrenches, characterized by a long service life, reliability due to durable materials, and a comfortable handle. At the same time, the power range of the devices varies, which allows you to choose the most suitable model. Popular options include GSR 18-2-LI Plus, GDS 18 E and GSB 18-2-LI Plus.
Makita. The brand produces models that are characterized by balance and versatility. Such a device will come to the rescue in those situations when wrenches are powerless. At the same time, the company provides the market with options in three versions: amateur, semi-professional and professional. Most popular models. 6904VH and TW0200.
Sparky. Convenience, compactness, ergonomics, high-quality solution to the task at hand. all this applies to the products of this brand. At the same time, the versatility allows you to use the tool for various purposes. Almost all users prefer the GUR 10.8Li HD model.
A wide assortment contributes to the selection of the most optimal option.
Type of food
Such tools also differ in the type of drive. There are two options. Electric wrenches operate only from the mains. A wide range of capacities allows you to choose the most optimal model. The direction of rotation (clockwise or counterclockwise) is set using the built-in controller. The weight of such devices varies between 1-9 kg. As power increases, so does the mass of devices. The advantages of this option:
- performance;
- reliability;
- extensive field of operation: automotive, heavy industry, petrochemical industry;
- versatility due to the large number of replaceable attachments and accessories.
The shock-rotary mechanism is the basis for the functioning of the devices. Among the main technical characteristics:
- power;
- number of revolutions per minute;
- torque.
The higher the parameter values, the higher the productivity. The technical parameters determine the mass of the apparatus. Ergonomic design and vibration-reducing material ensure reliability and comfort.
- wood;
- metal;
- plastic.
Compactness and ergonomics allow using the tool both for solving everyday issues and for performing professional tasks. Such a device is suitable for motorists, especially when a wheel has to be replaced on the road. Equipping the tool with additional accessories increases the functionality. The work is carried out in the same way as in the previous version. It is based on impulse rotation. Due to the direction switch and torque power regulator, the quality of the task and reliability are ensured. The design of the apparatus includes:
- handle;
- “body”;
- clamp;
- source of power.
The shock function only enhances the performance of the apparatus. The main technical parameter of this category of tools is the maximum torsional moment. With an increase in the indicator, the capabilities of the device increase. This value ranges from 100-500 Nm. It is worth paying attention to the frequency of impacts. In turn, voltage and capacitance determine the performance and operating time of the apparatus. As power increases, so does weight.
Additional functionality of devices
For greater safety and better quality of work, the equipment is equipped with auxiliary functions. The presence of such systems increases the capabilities of the devices. Most popular options:
Electronic speed control system. This option reduces the number of clamping rotations in the event that an obstacle occurs during operation. This parameter helps to eliminate breakdowns and prevents them.
Emergency brake. This option works in special cases. This, for example, jamming, hitting foreign objects. A special button, after pressing, stops the power supply, completely stopping the clamp. This option excludes defects.
Backlight indicator. This option allows you to perform tasks at night or in low light conditions. The indicator is located under the trigger. It allows you to clearly see the work surface even at dusk.
Another handle. This element provides reliability. It provides the user with a stronger grip on the tool when it is required to screw fasteners into a structure made of a material with a high density. The presence of rubber pads minimizes slipping during operation.
Brackets and straps are also used, allowing you to compactly store the instrument on the wall.
The choice of model is directly determined by the purpose of using the tool. When buying, power, speed and torque must be taken into account. These characteristics are the most important.
For example, the DeWalt DW292 model is suitable for domestic purposes, the Bosch GDX 18 V-LI option will be sufficient for service stations and tire shops, and professionals should give preference to more powerful modifications, for example, the Makita TW0350. The cost of devices is determined by the characteristics of the products.
Watch the video “How to choose a pneumatic impact wrench”
Criterias of choice
In order for the wrench to perform the necessary list of household tasks, you should choose it taking into account a number of indicators. The main requirements for the selection are technical characteristics, design features and convenience in everyday use.
For passenger
If it is necessary to use an impact wrench for repairing cars, the requirements are not as high as for trucks. The minimum torque is 250 Nm. For permanent use, it is allowed to purchase a tool with a torque of 600 Nm and fasteners M600.
If you plan to repair a car in an open area or in a garage where there is no possibility of connecting to the mains, it is worth choosing an autonomous version. Rechargeable battery powered equipment is wired free for mobility and ease of day-to-day operation.
Since the standard battery capacity is not enough for a long time, the self-contained version is not suitable for continuous operation and performance of work that requires a lot of time.
Functioning principle
There are a large number of varieties of tools with a similar structure and principle of operation. The wrench consists of a barrel handle, inside of which a functional mechanism is introduced that activates the operation of the engine, spring and chuck. Unlike a drill, the tool is equipped not with a drill, but with an elongated attachment for clamping a nut.
After starting the wrench, energy is supplied to the motor and gearbox, which includes the chuck. The additional spring provides reverse rotation for increased functionality. Modern types of tools have a speed adjustment function and interchangeable nozzles.
Impact sockets for impact wrenches
Socket heads are used to work with threaded connections, nuts and bolts in the tool. They are fixed in a chuck or spindle and transmit torque to the fastener. Standard heads have a cylindrical shape with a square or multi-faceted recess.
The main difference between the impulse impact head and the base head is the presence of a through hole for the pin. The presence of an additional hole is necessary for fixing the impact wrench on the impact version, which is used in work with increased load and is able to unscrew tight fasteners.
What compressor is needed for a pneumatic wrench
Having decided on the type of wrench, it is necessary to select the appropriate compressor for it. The mechanism must provide the required indicator of working pressure and compressed air consumption.
The optimum operating pressure for the cordless compressor is between 6.2-6.5 bar, but for a wider range of applications it is recommended to purchase the version with a maximum pressure of 10 bar. The air consumption of the nutrunner is indicated in the data sheet and should be 65-75 l / min.
Types of pneumatic impact wrenches and technological features
All pneumatic wrenches differ in the type of mechanism embedded in the body and the principle of action on the fasteners. Distinguish between impact and non-impact type of mechanism. Impactless varieties function due to the rotational action of the drive shaft. The tools are used for loosening small threaded connections. Impact wrenches affect fasteners through rotation of the drive shaft and impulses from the impact mechanism. The generated high impulses allow even rusty nuts and bolts of different sizes to be loosened.
For truck tire fitting
Freight transport is characterized by increased weight, thickened metal in the structure and constant high load on the base. Due to these features, nuts and bolts on trucks are tightened to the limit and it is impossible to unscrew them without specialized equipment.
In addition, during the long-term operation of vehicles, rust appears on the threaded joints, which creates additional difficulties in repair.
To work with truck parts, you need to purchase an impact tool with maximum power and torque. Due to the forceful action, the equipment will allow unscrewing corroded elements with a small investment of time and effort. The use of professional equipment eliminates the risk of damage to the thread, regardless of the complexity of the work carried out.
Types of pneumatic impact wrenches and technological features
All pneumatic wrenches differ in the type of mechanism embedded in the body and the principle of action on the fasteners. Distinguish between impact and non-impact type of mechanism. Impactless varieties function due to the rotational action of the drive shaft. The tools are used for loosening small threaded connections. Impact wrenches affect fasteners through rotation of the drive shaft and impulses from the impact mechanism. The generated high impulses allow even rusty nuts and bolts of different sizes to be loosened.
What compressor is needed for a pneumatic wrench
Having decided on the type of wrench, it is necessary to select the appropriate compressor for it. The mechanism must provide the required indicator of working pressure and compressed air consumption.
The optimum operating pressure for the cordless compressor is between 6.2-6.5 bar, but for a wider range of applications, it is recommended to purchase the version with a maximum pressure of 10 bar. The air consumption of the wrench is indicated in the data sheet and should be 65-75 l / min.
For passenger
If it is necessary to use an impact wrench for repairing cars, the requirements are not as high as for trucks. The minimum torque is 250 Nm. For permanent use, it is allowed to purchase a tool with a torque of 600 Nm and fasteners M600.
If you plan to repair a car in an open area or in a garage where there is no possibility of connecting to the mains, it is worth choosing an autonomous version. Rechargeable battery powered equipment is wired free for mobility and ease of day-to-day operation.
Since the standard battery capacity is not enough for a long time, the self-contained version is not suitable for continuous operation and performance of work that requires a lot of time.
Angle pneumatic pneumatic ratchets
Angular type pneumatic ratchets, by analogy with the standard version, are used to tighten screws, nuts, bolts and other fasteners. A distinctive feature is the ability to operate in a limited space due to the curved shape. Angle ratchets are widely used in tire shops, car services, and manufacturing plants.
The angular type of equipment has several features. The main ones are the following:
- the axis of rotation of the spindle is located at right angles to the body, which makes the tightening torque minimal;
- pneumatic ratchets have compact dimensions, which simplifies use in hard-to-reach places (for example, under a car hood);
- an automatic tightening torque controller is built into the body;
- basic technical parameters ensure a high level of performance.
Impact sockets for impact wrenches
Socket heads are used to work with threaded connections, nuts and bolts in the tool. They are fixed in a chuck or spindle and transmit torque to the fastener. Standard heads have a cylindrical shape with a square or multi-faceted recess.
The main difference between the impulse impact head and the base head is the presence of a through hole for the pin. The presence of an additional hole is necessary for fastening to the impact version of the impact wrench, which is used in work with increased loads and is able to unscrew tight fasteners.
Technical specifications
Regardless of the type of impact wrench, certain technical characteristics are inherent in it. The list of important parameters includes:
- limiting power;
- the number of speeds and the ability to adjust the rotation speed;
- the possibility of autonomous functioning;
- maximum number of revolutions and frequency of beats per minute.
Also, when buying equipment, you need to pay attention to the package bundle. In addition may include: battery, charger, technical documentation, storage case and warranty card.
Which wrench is better to choose for a garage, its types and technological features
The impact wrench is used for car repair and solving many household tasks. The tool will replace the usual socket head, with which it is not always possible to unscrew rusted parts. When equipping a garage, you should think about which wrench to choose for it so that it meets all the requirements for technical characteristics.