Electric impact wrench (how to choose and use)

Constant work with various fasteners is noticeably faster and easier if you have special tools at hand. One of them is a wrench, the main purpose of which is to work with threaded connections.

This tool is found in the hands of auto mechanics, in various auto repair shops, and is actively used on construction sites, in everyday life, and wherever it is necessary to work with nuts and bolts.

Device and characteristics

An impact wrench is a tool designed for unscrewing and screwing in bolts and nuts.

In essence, it is an advanced version of a wrench, speeding up and facilitating the process of working with threaded connections.

The simplest tool looks like a screwdriver or drill, however, it has a number of design differences.

Material

Since the impact wrench is often used to work with tight threaded connections, where a wrench is often powerless, its production uses materials that can withstand fairly high loads.

The body is usually made of metal and impact-resistant plastic (depending on the type of tool and its power).

The rubberized handle provides a good, strong grip even in the cheapest construction gloves.

It is also common to find a tool with rubberized elements of the main body for comfortable holding with two hands.

Some models are equipped with heat-resistant linings on the body.

The fact is that the tool gets very hot during intensive use, and such pads prevent burns.

The operating mechanism is made primarily of brass and steel.

Dimensions and weight

The weight of the impact wrench directly depends on its type, as well as on the materials from which it is made.

In addition, this parameter affects the usability.

For example, household one-handed models do not require serious effort; as a rule, they weigh up to 3 kg, which is equivalent to a drill or screwdriver.

At the same time, large two-handed models have a noticeable weight, which, when unscrewing a stuck nut of large diameter, reduces the load on the hands against rotation of the fastener.

As for the dimensions of the tool, they, in any case, should allow it to be used comfortably by the operator.

The length of household models is usually up to 40cm.

Such a tool does not take up much space when stored, for example, on a shelf in the garage.

The length of powerful professional tools often exceeds 60cm.

Cartridge (types of cartridges)

The impact wrench does not have a chuck, in the classical sense of the word.

Its place is taken by a rod - a spindle, shaped like a square on the working side.

This square is a seat for the nut head.

It should be noted that there are models where the shank has a hex hole of the HEX standard.

This allows you to use adapters - squares of different dimensions.

Such adapters can be used to operate socket heads in conjunction with screwdrivers.

Torque

The first parameter that you need to pay attention to when choosing a wrench is its torque.

It represents the rotational force (measured in Newton meters) generated by applying a force of 1 N to a lever 1 m long.

For comparison, the torque of an ordinary screwdriver in human hands is up to 9 Nm.

At the same time, the battery model produces up to 400 Nm, the pneumatic model – up to 1000 Nm, and the hydraulic tool breaks all imaginable records – around 20 thousand Nm.

It would seem that the greater the torque of the wrench, the better.

However, the statement is not entirely true.

The tool must be selected for specific tasks, which means it is more important to know the torque that needs to be applied to screw the nut.

The fact is that overly powerful models will simply break the thread.

And if you tighten the nuts on the wheels of, say, a car, the driver will not be able to unscrew them on the road without using the same wrench.

This is where the essence of the usefulness of the additional function of the tool is revealed - the ability to set the maximum torque, after overcoming which a special ratcheting mechanism will operate, preventing the fasteners from being overtightened.

Revolutions

The parameter characterizing the operating speed of the impact wrench is idle speed (without load).

For household work, low-speed tools are used, while professional models produce high speeds.

The dependence is simple: the higher the idle speed, the more fasteners they can work with.

Idle speed, depending on the specific model, varies from 800 to 3600 rpm.

Best load wrench

Tire fitting and repair of heavy vehicles involves the need to unscrew heavily tightened and stuck nuts and bolts. For these purposes, different types of load wrenches are used: electric, pneumatic, mechanical and manual. The latter are most often used to unscrew wheels directly for replacement on the road, the rest are used in stationary workshop conditions.

Peculiarities

Tools of this type are capable of developing significant forces with or without the use of shock-impulse effects. When repairing trucks, you have to unscrew large nuts, which determines a certain range of heads used.

Such devices are not characterized by a high rotation speed of the spindle with the nozzle due to heavy loads.

Characteristics

Electric drive power up to 1.1, kW.
Maximum torque from 3185 to 3500 Nm.
The range of used heads is from M18 to M39.
Output shaft rotation speed from 410 to 3200 rpm.
Impact frequency up to 75 beats/min.
Weight from 8.7 to 64 kg.
Pressure in the pneumatic system is up to 6.3 bar.
Capacity up to 238 l/min.

pros

This tool is specialized and designed for car repair.
Ease of use.
Great force and the use of shock to unscrew soured joints.

Minuses

All types of cargo impact wrenches listed, except for manual ones, can only be used in specially equipped and equipped workshops.

The need for personnel with good tool skills and appropriate physical characteristics.

A load wrench is a specialized tool and, accordingly, has a fairly high price. Purchasing such a device makes sense only for large workshops with large volumes of work.

Rating of the best models

The Polarus-12 electric impact wrench provides maximum force.
The best model in terms of functionality is Dino Paoli 256 BG.
The most reliable tool is Nordberg IT4250.

Working principle of the impact wrench

The shank with a nut head is driven by a motor through a gearbox, which are installed inside the wrench body.

NOTE
Some models of impact wrenches only turn in one direction - for screwing, i.e. they do not have a reverse function.

On universal models, the reverse motion (for unscrewing) is activated by a switch on the body.

The tool can be powered from a household electrical outlet or battery.

Pneumatic options use the energy of compressed air, while hydraulic options use the energy of liquid under pressure.

Types of impact wrenches

Modern versions of this instrument are divided into:

• Impactless (rotational) - a cheaper option, suitable for home use.

Manual

A tool or “meat grinder”, also known as a mechanical wrench, which unscrews nuts using the force of the operator.

As a rule, it is a cylinder with a reduction gear inside; it is called a torque amplifier (multiplier).

On one side of the tool there is a handle, the rotation of which sets in motion a rod with a head located on the opposite side.

Its design allows you to increase the physical effort on the element being unscrewed, thereby making the worker’s work easier.

To prevent the tool from turning in the opposite direction, it has a foot - a stop.

Often used to “break” nuts on car wheels.

Corded impact wrench

A power tool powered by stable household AC power.

Characterized by small dimensions and noise level.

Large power range, torque of some models reaches 6 thousand Nm, high efficiency.

Network tools have a simple mechanism for switching the direction of rotation of the head and a torque regulator.

Weight can reach 9 kg or more.

Reliability and high performance allow such impact wrenches to be used both in everyday life and in production areas, in the automotive industry, and in the production of heavy equipment.

Due to the huge number of adapters, this tool deserves the title of universal.

Cordless impact wrench

The main advantage is complete autonomy due to a removable battery.

Suitable for both home use and professionals.

Able to cope with nuts covered with a layer of rust.

They have a torque regulator (can reach 500 Nm) and a rotation direction switch.

Popular are impact models, the frequency of which reaches 3 thousand per minute.

Cordless options often have a brushless motor, which significantly extends their service life.

Pneumatic impact wrench

A popular tool in auto repair shops.

It has a metal body with a compressor hose connection system.

The air supply is regulated by a special screw.

Due to the lack of an engine it is light in weight.

The reversible mechanism allows you to quickly change the direction of rotation of the socket head.

There are both impact and non-impact models.

Hydraulic impact wrench

The main feature is the ability to control torque.

The engine function is performed by a hydraulic pump with a distributor.

All mechanisms are connected by quick-release couplings and high-pressure hoses.

Capable of developing torque over 10 thousand Nm.

Used where enormous force is required when tightening or unscrewing nuts.

Hydraulic tools are divided into end and cassette tools.

End models are used in routine work of unscrewing multifaceted fasteners.

Cassette copies can be solid or detachable.

One-piece models work on the principle of throwing on nuts or bolts.

The detachable version is used when working with fasteners in hard-to-reach places where it is impossible to use snap-on models.

Another advantageous feature of a hydraulic tool is the ability to use it under water, of course, if this is allowed by the manufacturer.

Gasoline impact wrench

The tool is powered by a gasoline engine.

It is characterized by autonomy and high power.

Often used in laying and repairing railway tracks.

According to the position of the chuck relative to the body, the tool can be:

• Lateral (angular) – the rod under the head is located at an angle of 90 degrees relative to the tool.

Used similarly to an ordinary spanner.

• End - the classic version, when the rod is removed from the body at its end.

It should be clarified that mains and battery options belong to the class of power tools.

This also includes various modifications, for example, a car impact wrench.

It is based on a twelve-volt DC motor.

The tool is powered by a car battery.

The current is supplied not directly from the power supply terminals, but from the cigarette lighter, which allows you to quickly prepare the impact wrench for work.

Speaking of cars, for heavy-duty vehicles, where most of the nuts are large, cargo pneumatic impact wrenches are produced.

They have an extended shaft, are capable of operating at a pressure of 8 bar, and weigh more than 10 kg.

Another subclass of impact wrenches is the torque tool.

Its difference is the ability to set a certain force (torque).

Often used in cases where it is necessary to tighten all the nuts of a mechanism with a specific fixed force.

The best electric impact wrenches

In everyday life and in small industries, electric impact wrenches are most in demand. Some models only require a 220 V socket and an extension cord, while others operate entirely from a battery. This is the best choice for garages, equipment repairs and workshops. Here is a rating of popular models that have interested our experts due to their characteristics or have many positive reviews.

Milwaukee M18 ONEFHIWP12-502X

Rating: 4.9

One of the most expensive electric impact wrenches with a battery, characterized by high-quality assembly and impressive characteristics. The model twists the tool with a force of 1491 Nm, accompanied by blows in the amount of 2400 per minute, which users like in reviews. There are four speeds for quickly changing modes. The battery capacity is 5 Ah, and the second one from the set will charge in just 60 minutes.

Experts included the impact wrench in the rating as a leader in comfortable work. The tool connects via Bluetooth to a smartphone, on which you can set the rotation speed, twisting force, and backlight turn-on time using the app. You can even create profiles with different settings and load them when changing the master, which is useful if several people use the impact wrench. The program will allow you to keep track of operating hours and statistics.

Advantages

Full rubber handle;
brushless motor with long service life;
precise installation and control of settings;
huge torque of 1491 Nm.

Flaws

weight 3.2 kg quickly tires the hand;
the phone gets dirty from frequent adjustments in the workshop;
high price;
There is no torque adjustment on the body (only through the app).

DeWALT DCF899P2

Rating: 4.8

Universal electric impact wrench with a metal housing around the gearbox, equipped with three speeds. It has a rubberized handle with inserts for ventilation. It is equipped with two batteries with a capacity of 5 Ah and a ½ inch cartridge. There is a reverse and a shock function up to 2400 per minute. Supplied in a convenient carrying case. The model is quite powerful - in reviews, owners boast that the wrench unscrews a 32 mm nut in 8 seconds at maximum speed. The motor here is brushless, so it will last a long time and does not require maintenance.

According to our experts, the impact wrench should be in the rating due to its combination of delicacy and torque. Despite the indicator of 950 Nm, the tool will be able to carefully tighten the equipment with occasional smooth pressure on the trigger. This is useful on medium-sized nuts and bolts of 17-21 mm, so as not to tear off the equipment.

Advantages

there is no unpleasant return to the hand;
brushless technology;
bright backlight;
two batteries.

Flaws

heavy (3.3 kg) for frequent everyday use;
strong cracking sound when unscrewing;
no protective functions;
The reverse switch is in an inconvenient place - it gets touched during use.

BOSCH GDS 18 V-LI HT 0

Rating: 4.7

German electric impact wrench from a trusted brand. It has a twisting force of 650 Nm and a rotation speed of up to 1900 rpm. When tightened, it strikes at a rate of 2100 per minute. There is no step-by-step speed change, but there is a smooth electronic speed control by pressing the start button. The tool is designed for use with Cool Pack batteries, which have a long service life. Users in reviews share that a charge with a 4 A/h battery is enough to “change shoes” of one car. Although according to the instructions the model is designed for M20 bolts, in practice it copes with equipment up to M22.

Experts paid attention to the impact wrench and added it to the rating due to the beveled shape of the gearbox. This makes the tool more convenient for use in hard-to-reach places, such as when repairing car suspension.

Advantages

electronic overload protection is provided;
spring-loaded ball in a cartridge;
there is a backlight;
battery status indicator.

Flaws

only one speed;
the battery will have to be purchased separately;
no case or charger;
weight 3 kg.

Makita TW0350

Rating: 4.7

Network impact wrench from a well-known manufacturer. Consumes 400 W per hour of operation and produces a torque of 350 Nm. Made in a plastic case with a metal gearbox. Suitable for long-term use due to wide cooling holes on the side and rear. The speed of rotation and beats per minute is the same and amounts to 2000. The reverse function is implemented by means of a double trigger, where when you press the upper part, it rotates clockwise, and when you press on the lower part, the reverse action is triggered. Users in the reviews like the model for its simplicity and unpretentiousness - it easily unscrews the nuts on the hubs, tightened with a wrench.

The impact wrench is included in the rating due to the rubber protection of the gearbox. This is useful when installing complex structures, where the tool often hits the walls in narrow places. The rubber layer softens impacts and maintains the integrity of the case.

Advantages

easy replacement of brushes through service hatches;
correct weight distribution in the T-shaped body;
economical consumption of electricity;
comes with a case.

Flaws

air blows directly into your face when working;
one speed;
bulky due to the elongated body;
inconvenient fixation of heads with a pin takes more time when changing equipment.

BOSCH GDR 10.8-LI 2.0Ah x2 L-BOXX

Rating: 4.7

The product belongs to electric impact wrenches, but is more designed for screwing in fasteners in the form of self-tapping screws. To do this, the device was equipped with a hexagonal chuck for bits. But you can install an adapter in it and tighten small nuts and bolts up to M8. The impact wrench operates on a 2 Ah battery and produces speeds of up to 2600 rpm with 3100 blows per minute. Its maximum torque is not the greatest - 105 Nm, but it is quite enough for small fasteners. LED lighting helps perform processes in dimly lit areas without additional flashlights and lamps.

Owners in the reviews like the fast battery charging in 60 minutes, light weight and ease of manipulation. We included the impact wrench in the rating due to its compactness. The length of 137 cm will allow you to insert a power tool inside the body of a washing machine, microwave oven, or unscrew parts under the hood of a car. We recommend that appliance repair specialists and builders take a closer look at it.

Advantages

comes in a case;
two batteries;
works with impulse;
weighs only 1 kg.

Flaws

restriction on working with equipment up to M8;
you can’t work in the cold;
if you overexpose it, it will easily break the internal cross in the screw;
flimsy design of the case for transportation.

RYOBI R18IW3-0

Rating: 4.6

The best electric impact wrench in terms of price and quality from a well-known brand. Operates from a replaceable 18 V battery and produces 400 Nm. Equipped with a convenient battery status indicator. Rubber pads reduce vibration and do not slip in your hands. The spindle rotation reaches 2900 rpm and there is a tangential impact of 3200 per minute. The speed is adjusted electronically as the trigger is pulled. At the top there is a speed switch with three positions. In reviews, owners share that on R18-19 wheels, three clicks are enough and everything will be tightened to the desired level.

Experts added the impact wrench to the rating due to the optimal weight of the power tool of 2 kg. It fits comfortably in your hand and is suitable for long-term use throughout the day. Illumination in the form of three diodes on the gearbox provides better visibility and allows you to use the impact wrench in complete darkness.

Advantages

attractive price;
3 speeds for quick transition to different tasks;
the handle and the back of the body are rubberized;
unscrews wheel studs on SUVs.

Flaws

no battery or charger;
torque without limiter (always at maximum);
the bits have play in the adapter included in the kit;
To replace the brushes you will need to disassemble the housing.

Makita TD0101

Rating: 4.5

A corded tool from Makita, positioned as a screwdriver. It is powered by a 220 V network and has a power of 230 W. Equipped with a bit holder, a convenient reverse switch and produces a torque of 100 Nm. The spindle rotation reaches 3600 rpm, and the productivity is twice as high as screwdrivers due to blows of 3200 per minute. User reviews like the model due to the ability to quickly change brushes, savings on battery costs and ergonomics. But everyone complains about the hot gearbox, which, however, does not affect performance.

Our experts recommend using a rated impact wrench during construction and repairs for the installation of metal profiles or corrugated sheets. The model is distinguished by numerous rubber pads that reduce vibration. The handle with a wide stop at the end makes it easy to hold and manipulate throughout the day.

Advantages

fastening in the handle for installing replaceable bits;
long-term operation from the network;
light weight 1 kg;
increased vibration protection.

Flaws

the wire exit slightly interferes with access to tight spaces;
one speed;
only suitable for M10 equipment;
The power cord is of high quality, but short (2 m).

Bort BSR-12X

Rating: 4.4

Budget option with good characteristics. The impact wrench produces a torque of 380 Nm and promotes high productivity thanks to its impact function and speed of 3400 rpm. The device is powered from the car's on-board power supply at 12 V. The ½-inch square socket fits common heads and two are included in the kit, which reduces equipment costs. The model weighs 2.6 kg, supports electronic adjustment and reverse rotation. The power is quite enough to rotate the wheels of the R 18, but the owners in the reviews recommend using a power tool with the engine running, otherwise you can drain the car’s battery.

According to our experts, the impact wrench should have been included in the rating due to the power supply of the device. The model is equipped with a connector for a car cigarette lighter, which allows you to work in the garage and even in the field, and not depend on the capacity of the built-in battery. The price of the product is the most affordable in the category.

Advantages

complete with case and 17/19 and 21/23 mm heads;
there are two fuses protecting the on-board network;
tighten the wheel bolts to the 4th click;
attractive price.

Flaws

the large gearbox makes it difficult to get into hard-to-reach places;
completely plastic body;
Closely located reverse button;
The range is limited by a wire that is difficult to find an extension cord for.

Advantages and disadvantages of each type of impact wrench

Network models are distinguished by high power and efficiency, low noise during operation, low cost, but at the same time they are tied to a power source.

Battery options do not have this disadvantage, but have less power.

Among the battery models there are also quite powerful ones that can cope with complex work.

Pneumatic models are lightweight, shock-resistant, do not heat up, and have a high clamping force.

The downside is that it requires a compressor to operate, which is also very noisy.

Hydraulic models have high power, can cope with any fastener, are resistant to moisture, can work under water, and are suitable for self-repair.

However, they need to be connected to hydraulic systems, which are expensive.

Gasoline models are mobile, produce high clamping force, but are noisy, heavy and bulky.

All impact wrenches have one big drawback - each model has a specific spindle square size.

The heads must be selected according to this size.

• 1/2 inches – the most common size in everyday life;

• 3/4 inch – the size most common in auto repair shops and services;

• 3/8 inch;

• 1 inch – the square size of the most powerful impact wrenches used in the production of power plants and large-sized equipment.

The size of the spindle square also affects the loads that the socket head can withstand.

As the size of the square increases, the thickness of the head walls increases, and hence its strength.

The dimensions of the heads are tied to the dimensions of the squares due to the design limit of their strength.

In other words, it is impossible to make sufficiently strong small heads with thin walls for large squares.

For impact wrenches, both single-sided and double-sided heads are sold, usually in sets, along with an adapter.

In the second option, both sides are working, and the place of fixation (fitting) of the adapter is in the center of the head.

The adapter itself is, in fact, a small extension cord.