Manual impact wrench - how to work with this tool

The purpose of a wrench and its difference from a screwdriver

The purpose of this tool can be guessed from its name. An impact wrench is needed to tighten and loosen nuts and bolts with significant force: some models can develop a force of up to 65,000 Nm (Newtons per meter). Many craftsmen who have not encountered this tool confuse it with a screwdriver, apparently due to its external resemblance to the latter. And the main difference between the tools is the different type of cartridges. But in fact, the impact wrench has many more differences, which turn into a huge advantage when compared with a screwdriver.

So, what is the difference between a screwdriver and a wrench? Most impact wrenches are equipped with a pulse-impact clutch, but it differs from the same hammer drill clutch in that the force is directed not along the axis of the unit, but in the direction of rotation of the chuck. The impact (pulse) mechanism operates as follows: the device drive rotates the cartridge through a massive coupling element until the force reaches a certain threshold. Next, the leading element of the clutch is released from engagement and accelerates; the element accelerates within an incomplete revolution, after which it strikes the cam located on the axis of the cartridge. The massiveness of the element and the speed it gains create a high torque, thanks to which it is possible to “break off” stuck bolts and nuts.

Due to the high discharge current, even expensive, professional cordless impact wrenches can only work continuously for 15-20 minutes, which cannot be said about screwdrivers.

Based on the above differences, it is not advisable to use a wrench instead of a screwdriver.

Design and principle of operation

The driving element of the pneumatic impact wrench is represented by a pneumatic motor including a rotor. It converts air pressure into rotation. To supply air to it, there are two channels, approaching from different directions (for models with reverse). The main functional part is a cylindrical stop with a replaceable head. To transmit the rotation of the rotor to it, a frame is used, which also holds two hammers, represented by metal rings. The housing is equipped with a trigger, a fitting for a compressor hose, and a handle. Some models are equipped with a removable additional handle designed for installation in various positions. Impact wrenches are equipped with a set of attachments. The most durable among them, made of hardened steel, are black in color. They are much more durable and shock resistant.

Pneumatic impact wrenches are powered by a compressor, just like other pneumatic tools. The principle of operation of a pneumatic impact wrench is to transmit, through hammers and a frame, the rotation of a rotor driven by compressed air to the stop by acting on the blades.

The principle of operation of the reversing mechanism is to switch the air supply channels, as a result of which the direction of rotation of the rotor changes. This makes it possible to unscrew and tighten the fasteners.

If it is necessary to apply a lot of force to the fastener, the hammers rotate when the stop is in a stationary position, as a result of which the hammers engage with it. Then they make a reverse revolution, gaining inertia, and, approaching the point of engagement, they hit the stop. If the position of the fastener is maintained, the operation is repeated. Because of this, impact wrenches are suitable for tight fasteners. A non-impact impact wrench does not have this capability.

Thus, impact wrenches are differentiated into those equipped with an impact mechanism and those without it. Impact models are characterized by high torque and an increased risk of breaking the bolt head and threads.

Types of tools

The impact wrench, being a highly specialized tool, performs quite an impressive amount of work. It is difficult to say which impact wrench is better, because the type and power of the tool is selected based on the goals and tasks that it has to perform.

1. Electric. A high-speed, powerful and precise unit with virtually no vibration. The electric motor of the device operates from a 220V network and is equipped with a fan for better cooling, which allows the tool to operate for a long time.

   

2. Rechargeable. This type of impact wrench is convenient due to its mobility and allows you to work away from the electrical network. The battery device can be used in construction when installing various panels, laying communications and for performing minor installation operations.

   

3. Pneumatic tools. As you might guess, the prefix “pneumo” means that compressed air is used to set the device’s cartridge in motion. The latter is supplied through a high pressure hose connected to the compressor. Due to the absence of a motor, pneumatic impact wrenches are distinguished by their lightness and do not cause fatigue to the operator during operation. Also, the air impact wrench is not afraid of overheating and can be used in places where the use of electric tools is unacceptable (rooms with high humidity, places with a high risk of explosion).

   

4. Hydraulic. The drive in this tool is a hydraulic pump with a distributor. The device operates on the following principle: the force developed by the hydraulic cylinder during the translational movement of the piston is converted into torque through a ratchet wheel. A hydraulic impact wrench, depending on the model, can develop colossal force, sometimes reaching up to 65,000 Nm.

   
   It should be noted that there are two types of hydraulic impact wrenches: snap-on and cassette. The picture below shows a socket tool.

   

   The following photo shows a hydraulic cassette type of unit. It is usually used in places where it is impossible to reach with a spanning tool.

   

5. Petrol. This type of impact wrench is mainly used in the repair or construction of railway tracks. A gasoline impact wrench is convenient to use far from power supply, in difficult field conditions, thanks to its complete autonomy.

   

6. Geared. This is a manual multiplier impact wrench, popularly called a “meat grinder”. A gear wrench consists of a planetary gearbox housed in a metal housing. When the handle is rotated quickly, the speed is transmitted through the gearbox to the output shaft, which begins to spin much slower than the handle, but with much increased force.

   

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Thanks to this hand tool, you can unscrew fasteners that cannot be “torn” out of place in the usual way. It is often used in the field for trucks, buses, and tractors as a wheel impact wrench.

How to use it correctly

It should be noted that the operating technology of different types of impact wrenches differs, which is explained by the design features of such a tool. For example, the operation of a pneumatic impact wrench involves the following stages of work:

1. Assemble all elements according to the included instructions.
2. Installing an impact socket of the selected size onto the spindle.
3. Connection to the compressed air system.
4. Start the device by pressing a special lever.
5. Applying pressure directed towards the twisted surfaces.
6. Achieves optimal tightening torque in approximately six seconds.

   
   Idle operation of the device leads to premature wear

You cannot keep the impact wrench loaded for a long time, which can be the main reason for repairing the impact mechanism. During operation, you need to beware of reactive effects and prevent “idle” operation of the device. After completing the work, turn off the compressed air system, disconnect the hose and close the air supply hole.

The use of mechanical impact wrenches, which act as a torque amplifier according to known physical principles, is distinguished by its special features:

1. Assemble the tool in accordance with the instructions supplied by the manufacturer.
2. Select size and install head.
3. Install the device on the fastening element.
4. Place the body stop of the tool on the nearest nut.
5. It is enough to actively rotate the handle.
6. After removing the fasteners, remove the device.

When working with such a mechanical tool, the location of the wheel and the type of work being performed must be taken into account.

Technology of operation of network and battery devices:

1. The start of work is carried out on long strokes.
2. Pulling out rusted or jammed fasteners is performed in reverse mode.
3. To change the direction of movement, a two-position switch is used.

It is necessary to complete tightening or unscrewing with the shortest and strongest strokes necessary for highly reliable connections with bolts.

Impact wrench selection options

When choosing a tool, you need to decide for what purposes you are going to use the impact wrench: household or professional . Their main difference is the power and duration of continuous operation. Household appliances have low power, overheat quickly (applies to network devices), and the working units in them are made of less durable materials than in professional-class tools. The device's power of 400 W will be enough for home use. If we talk about the rotation speed of the cartridge, then for domestic needs 20-40 rpm will be enough. A professional tool should have a speed of about 1500 rpm.

When choosing a battery-powered tool, pay attention to the type of battery. Typically, household devices use nickel-cadmium batteries, which cannot be recharged if they are not fully discharged, while professional devices use lithium-ion batteries, which can be recharged at any stage of battery discharge.

But it is worth knowing that lithium batteries are afraid of being completely discharged, which causes them to lose capacity and fail.

We should not forget about additional functions that increase the convenience of working with the tool.

1. Impact mechanism. The instrument can be either percussive or unaccented. An impact wrench will be useful when tightening “important” fasteners, such as car wheel nuts, where a lot of force is required both when tightening and unscrewing. An unstressed tool will not cope with such a task.
2. Adjusting the tightening force. It is not recommended to neglect this function. For example, if you have to tighten nuts with “vulnerable” threads, then without a force regulator they will break off in 1 second. Also, a wrench with adjustable torque allows you to tighten connections evenly, which is useful when installing car heads.
3. Gearbox type. A pistol-shaped impact wrench does not always allow you to solve all the issues during repair and installation work. Sometimes fasteners may be located in places inaccessible to “pistol” type devices. Therefore, for such purposes it is customary to use an angle wrench.

   

4. Built-in lighting. A very convenient addition to the tool, especially when repairing a car.

Also, when choosing this tool, pay attention to how it fits in your hand, whether the handle is comfortable, how much weight the device has, where the start button is located, etc. Ergonomic parameters determine the comfort of use.

For a better understanding of which tool to choose, below is a rating of the most popular models of various types of impact wrenches.

Applications and advantages of pneumatic impact wrenches

Pneumatic or pneumatic impact wrenches are widely used:

• in automobile repair shops,
• automobile assembly lines,
• heavy equipment manufacturing,
• in the assembly of heavy equipment,
• in maintenance,
• in the production of machine tools,
• in large construction projects.

They have some clear advantages over electric keys.

Below are 5 benefits of using a pneumatic impact wrench:

• high efficiency;
• high versatility;
• ease of use;
• high strength;
• high reliability.

Electrical corded tool

DeWALT DW 292

This is a corded impact wrench powered by a 220 V mains voltage. The unit has good torque (440 Nm), a power of 710 W and can produce 2700 blows per minute.

• the gearbox is in a metal case;
• there is a striking mechanism;
• good torque indicator.

• the reverse switch often gets touched if you work with gloves;
• There is no torque regulator.

Hitachi WR22SA

Hitachi WR22SA is a professional device that allows you to unscrew and tighten hardware with a thread diameter of no more than 24 mm (M24). The tool can be used for cars.

This corded impact wrench has a torque of 640 Nm, a power of 850 W and a speed of 1800 rpm. The entire body is made of aluminum, which increases the strength of the unit and increases heat transfer. Therefore, the tool is often purchased by car enthusiasts for the garage. With its help, you can unscrew almost any “stuck” nut on a passenger car.

• reverse is switched when you press the top or bottom of the trigger;
• high torque;
• high-quality assembly;
• presence of an additional handle;
• high performance.

Disadvantage: according to reviews from device owners, electric impact wrenches of this model are sometimes subject to overheating, which occurs in the mechanical part of the device.

DeFort DCW 12

DeFort DCW 12 can also be called mains-powered, but this impact wrench operates on 12 volts. It has a torque of 350 Nm and develops a maximum of 3300 rpm. The package includes an adapter that allows the device to operate from a car cigarette lighter. There is also an adapter with alligator clips to connect the device to the battery.

This device is mainly used for passenger cars.

• sufficient power for tire mounting;
• presence of reverse;
• small dimensions;
• car tool, since there are adapters for connecting to the battery and cigarette lighter;
• pulse mode;
• presence of a case.

• no additional handle;
• There is no adjustment of clamping force and rotation speed.

Delta Turbo-2000

The most powerful tool in this segment is the electric rolling impact wrench.

It is used mainly for trucks, when mounting wheels. Delta Turbo-2000 is a load impact wrench operating at 380 V and with a power of 1500 W.

It also has a square one-inch chuck and can produce up to 2,500 Nm of torque, which should be enough for wheel bolts.

Since the device weighs 65 kg, it is installed on a chassis.

• sufficient torque for efficient operation;
• availability of chassis;
• convenient height adjustment;
• speed regulator

• operation only on voltage 380 V;
• the movement of the unit is limited by the length of the cable.
• high price.

Electric cordless tool

Bosch GDR 10.8-LI

This is an impulse impact wrench, which we can say without exaggeration that it is one of the best devices in its segment . This tool runs on a Li-Ion battery with a voltage of 10.8 V, has built-in battery protection against complete discharge and overload, and is compact in size and weighs only 1 kg.

It is very convenient to use when working when the fasteners are at a height higher than the height of the master.

The device has a torque of 105 Nm, a spindle speed of 2600 rpm and a number of pulses per minute of 3100. The Bosch GDR 10.8-LI is successfully used both for household repair and installation tasks, and for professional use.

• high power;
• presence of battery charge indicator;
• short charging time;
• compact size and light weight;
• conveniently located reverse switch;

• as with all battery-powered impact wrenches, the main drawback is the short operating time;
• handle ergonomics.

Bosch GDS 18 V-LI HT

This is the most powerful cordless impact wrench with an 18 V battery, as it has a torque of 650 Nm.

Thanks to the metal gearbox housing, the device is highly durable and reliable. The device weighs 3 kg, and it can be called the lightest among devices of the “High-Torque” class, that is, among tools with high torque. Therefore, if you need a powerful and mobile tool, then it is better to choose a wrench of this particular model.

• metal gearbox housing;
• high torque.

The only downside to this tool is the price. You can buy it for about 15 thousand rubles.

Makita 6940 DW

This impact wrench is an angle tool and complements the range of cordless impact wrenches.

This model has a length of 370 mm and a height of 60 mm. Thanks to these dimensions, the side tool is effectively used in hard-to-reach places. The maximum torque value of the impact wrench is 30 Nm, and the rotation speed is 2000 rpm. In addition, the device can produce 2700 pulses per minute.

• small dimensions;
• the ability to work in inaccessible places;
• You can work with one hand due to the small diameter of the case;
• pulse operating principle;
• presence of a case.

• low torque level;
• low battery capacity.

Alkitronic EFCip series

The impact wrenches of this company are industrial tools.

Any EFCip series impact wrench has a synchronous motor (no brushes), making the drive subject to less wear and maintenance.

The body of the device is also durable, as it is made of aluminum alloy. The EFCip series units operate from a voltage of 100-235 V with a frequency of 45 to 66 Hz and can develop torque in the range from 60 to 6500 Nm.

The Alkitronic EFCip industrial device is a torque wrench, since the progress of its operation is monitored by a microprocessor, which, when the required torque (tightening force) is reached, turns off the engine. All necessary parameters are displayed on the LCD display located on the back of the instrument, where the control buttons are also located. In the nose of the unit, near the gearbox, there is a non-rotating gear wheel, onto which a special stop attachment is placed.

Based on the above data, the Alkitronic EFCip is the best impact wrench of all those listed above.

• high torque;
• electronic torque control:
• LCD display;
• metal case;
• possibility of installing a stop;

The main disadvantage of this unit is its high cost.

Reviews

As I said at the very beginning, the TW0200 impact wrench has been working properly for more than three years and the only drawback that has surfaced is the rather short original cord. If you want to change all four wheels from one outlet without moving the car, you can’t do it without an extension cord.

What can I say in conclusion? The thing is cool: reliable, powerful, convenient and saves time. Expensive? How to look: no more expensive than a good average smartphone, but it definitely saves time and effort. However, the dilemma here is classic: buy and forget, or buy a Chinese handicraft every year or two? On the other hand, when changing wheels (or brake pads, for example), I’m sure that I won’t have to turn the nuts by hand.

Uned

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I want to write my review about the impact wrench. My father bought it three months ago. He bought it on sale for 6,900 rubles, with a 5-year warranty. This impact wrench came at just the right time, as a garage renovation was planned. There the structure is connected with fastenings with bolts and nuts. Well, what can we say, the impact wrench did not let us down. A very powerful tool. The battery lasted for 4–5 hours of normal operation. By the way, its speed reaches 2200 per minute. What’s also nice is that there is a backlight indicator, which came in handy for us, since we worked until late in the evening.

By the way, it fits very comfortably in the hand, and its weight is only 2.2 kg. But this weight is not felt at all when working. True, there was only one battery included. But what's cool is that it charges quickly. You put it on charge for 45-50 minutes, and again for 3-4 hours of work. Voltage 18 V.

Ivan 35

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I purchased it in the spring of 2015 and immediately purchased drum heads for it. I’ll say this: I helped disassemble and reassemble the quad more than once. The wheels of the quad are unscrewed and tightened at once. The moment is enough. I tore the stuck nuts out of place. Helped a lot. But bad luck - literally immediately the lock of the replaceable heads (the same ball on the pulley) broke. And now, if you don’t watch, the head and the nut fly away very cleverly.