How to choose a compressor for your impact wrench


Before choosing an industrial nutrunner compressor, decide on the pneumatic nutrunner itself. The most important technical characteristic of a pneumatic impact wrench is the torque. The amount of torque has a direct influence on the kind of operations that can be carried out with the wrench, as well as the timing of those operations. Obviously, the higher the torque, the more you can tighten a threaded connection (or, conversely, unscrew a “stuck” nut). But on the other hand using an excessively powerful impact wrench can cause damage to the thread connection (thread breakage). Therefore, it is very important that the torque is appropriate for the specific tasks to be performed.

If we give a numerical estimation of the torque parameters, then pneumatic wrenches have a range from several tens to several thousands of Nm. Impact wrenches for domestic and semi-professional work should have torques between 200 Nm and 600 Nm. For more serious jobs you need wrenches with torques starting at 1000 Nm and more.

The second important technical feature of an impact wrench, the square footage (spindle dimension), also depends on the torque rating. Here it’s simple: the higher the torque, the larger the size of the square. Standard range of shank square dimensions are measured in inches. The most common are ½, ¾ and 1″. 1/2 in. square torque wrenches are typically used for domestic and semi-professional applications and ¾ and 1 in. square torque wrenches for industrial applications.

The other way to look at the choice of spindle square size is. According to wrench companies, the size of the square is related to the size of the nut (bolt head) that needs to be unscrewed/screwed:. If the wrench size is 10 to 21 mm, then a ½” square wrench is suitable;. If the wrench size is between 24 and 36 mm, then a ¾” square wrench is suitable;. If the wrench size of the nut is 41 mm or more, a 1-inch square wrench will do.

The third important technical characteristic of a impact wrench is the air consumption. It also depends to a large extent on the torque: the higher the torque, the higher the air consumption. Impact wrenches with ½” square drive have an air consumption of 150-250 l/min; the more powerful ones have an air consumption of 300 l/min and higher.

As an example here is a summary table of the main characteristics of stud wrenches from one of the world’s leading producers of these products.

Product Name Torque, Nm Air flow, l/min
1/2″ nutrunner 270. 810 170. 230
¾” impact wrench 680. 1600 270. 340
1″ nut 1630. 4070 800. 1130

General approaches to choosing a compressor

After choosing the impact wrench, proceed to the selection of the air compressor. The compressor to which the impact wrench will be connected must meet two requirements:. Provide the required working pressure of compressed air;. provide the required compressed air flow rate.

The standard working pressure required for most wrenches on the market is 6.2-6.5 bar. Therefore, the compressor to be used for work, should have a maximum working pressure of 10 bar (or, in other words, to work in the pressure range of 8-10 bar).

How to choose a compressor for the service station by capacity? The Wrenches data sheet shows the air consumption of the. However, in practical work, the impact wrench is not used continuously, but only intermittently. That’s why every pneumatic tool (including impact wrenches) has its own so-called utilization factor. In our case it is equal to 0,2-0,25. Therefore, if it is stated in the passport of the impact wrench that its air flow rate is 300 l / min, then for the actual calculations should take into account the value of 60-75 l / min.

If more than one impact wrench is planned, the risk of simultaneous operation must also be taken into account. It is determined by the synchronism coefficient of equipment operation, the values of which are given in the table below.

Number of compressed air consumers 1 2 3 4 5
Synchronization factor of the equipment 1,0 0,95 0,91 0,87 0,84

Thus, the previously calculated value of the total compressed air consumption must be multiplied by the corresponding simultaneity factor. And choose a production air compressor on the basis of this value.

The further order of choice of the compressor is exactly the same as in his choice for any other equipment. There are two types of compressors: piston and screw type. If the air consumption is up to 1000-1200 l/min, a piston compressor can be used; if higher, a screw compressor is better.

On the other hand, the choice of compressor type depends on the nature of work: if it is a one-or-two-shift operation, it is quite suitable piston compressor; if the mode of operation around the clock, you need a screw compressor.

Questions of practical use of a screwdriver

How to choose the right air compressor

Pneumatic wrenches help you tighten or loosen large numbers of nuts and bolts quickly. They are driven by compressed air delivered through a hose from an air compressor. This pneumatic tool is widely used on assembly lines, construction sites, service stations or tire changers, in car repair shops and garages.

Although the purpose of the pneumatic screwdriver is purely professional, today the for this tool are low, so it is available to a wide mass of consumers. However, not every enthusiast or car enthusiast needs it. There are several reasons for this:

1) Use of a pneumatic tool is justified in the case of large volume of work when cordless or manual tools are ineffective. For example, you would have to spend more than an hour under the car if you fasten the front cross member with an ordinary ratchet. The pneumatic impact wrench significantly speeds up the work process and prevents tedious jobs.

2) Cheap 1/4″ and even 3/8″ wrenches do not always have enough torque to reliably tighten all nuts and bolts used in cars. Powerful professional models are too much for the average car enthusiast and are expensive.

3) In addition to a pneumatic nutrunner, a compressor is also necessary, but it also costs money and takes space in the garage.

The main advantages of pneumatic wrenches are high power, ability to work in an intensive mode. No electric current inside the tool, so it is safe to use in damp, dusty, or explosive environments. Air tools are also more compact and lighter than electric tools.

The main disadvantage of air tools relates to power control. Not every heavy-duty model is acceptable if low torque is needed. Uncontrolled excessive power leads to destroyed or damaged bolts.

Impact Wrench Accessory That You ABSOLUTLY NEED TO SEE! (It will save you hundreds of dollars)

Working pressure, air flow, and compressor compatibility

To ensure that the power and performance of the air tool matches the factory specifications, it is important to consider the air flow and working pressure. For ideal work of the pneumatic wrench it is necessary that the compressor capacity was 20-30% higher than air consumption, and the pressure at the compressor outlet was 1.5-2 bars higher than the working pressure of the tool to be connected. For example, 3/8-inch models consume 50-120 liters of air per minute and require a working pressure of 6.6-6.3 bar. As a result, they will need a compressor with specifications of 65-150 l/min and 8-10 bar.

Also note hose diameter, size of adapters. The inner diameter of the hose must be at least 3/8˝ (9.5 mm), and if the line length over 8 m requires a hose with a diameter of 12 mm or more.

Read more:  How to cut roller blinds to length

Air feed diagram for an air screwdriver

Tip: Air tools benefit from having an oil lubricator on the air supply. Constant lubrication of the air tools increases service life. The lubricator should be checked regularly and filled with oil.

Impact or no impact mechanism

Pneumatic screwdrivers are available as impact and hammerless screwdrivers. In the first case, not only does the spindle rotate, but it also creates powerful shock pulses. It helps to unscrew tight, heavily rusted and large nuts. Impact wrenches are often used to loosen car and truck wheel nuts, so they are ubiquitous in auto mechanics’ toolboxes. They are used at service stations, tire dealers, and service centers. This is the tool you see at the car racing circuit during a wheel change at a PIT stop.

The hammerless models are used for delicate jobs where it is important to minimize the risk of thread stripping. They are often used in assembly shops, home locksmith shops.

choose, compressor, your, impact, wrench

Maximum torque

They can be between 30 and 5000 Nm. If this value is insufficient, it is not possible to securely tighten the nut. If the value is too high, there is a risk of damaging the threads.

As a rule, a fastener tightened to a certain torque requires the same amount of force to remove. For example, if you tighten the nut with 100 Nm, it would take an equal amount of force to loosen it, but this is under ideal conditions. Some factors change this rule, because the fasteners weaken over time from vibration, or vice versa, “stick” because of corrosion.

So when selecting an air screwdriver you must take into account the effort required to loosen or tighten the fastener (the specific numbers will be explained in the paragraph about the drive-in square below).


Depending on the model of the impact wrench the spindle will rotate between 3000 and 11000 rpm. Higher speeds increase productivity (tightening is faster), but reduce control of the tightening process and therefore the risk of thread breaks. High RPM helps to unscrew cranking parts (e.g. pulley nuts on an alternator, car suspension strut nuts). Reduce rotor speed by adjusting the pressure in the compressor or by a special mechanism.

Squareness of fit

This is directly related to the size of the fasteners the tool can handle. If you consider most threaded connections used in automobiles or households and consider the torque requirements, the 3/8 and 1/2 inch fit squares are the most suitable and common.

When it comes to auto repair shops and garages, then:

Some manufacturers offer sets of wrenches of different sizes and power, completely covering all the needs of a professional mechanic.

Weight and dimensions

Once you’ve picked a square fit, pay attention to weight. Large, heavy tools are good for their power, but uncomfortable for prolonged use. Too light, but too powerful an air wrench can twist your wrists under great strain. Optimal weight for one hand is about 2.5 kg. Dimensions are also important. For ease of use in tight spaces when repairing a passenger car, the length of either side of the tool should be up to 250. 300 mm.

How to choose a tire compressor, what features to rely on

Pumping speed

I think that everything is clear with this parameter, but it is worth to clarify which one you need for your car. It is best to be guided by the diameter of the wheels when choosing this parameter:

Compressors with speed of 50 l/min can be used to connect to the pneumatic tools. Speed 100 l / min with a crossover wheel or sedan to cope with less than a minute, but the cost of such devices is not budget, because compressors with such characteristics are often bought for trucks and special equipment. They can also be used to connect to pneumatic tools.

If you choose a compressor for inflating your boat, mattress, etc.д., then you should not choose models with low capacity from the low price segment. In this case, they will have to work for a long time and a cheap compressor can simply not withstand such a load.

How to Choose an Air Compressor

Continuous operation time

Some models can run for only 10-15 minutes without stopping, after which they need to pause. At the same time protection against overheating in these models is not always provided, so the duration of continuous operation should know yourself and turn off the compressor at specified intervals.

Maximum pressure

This parameter defines which wheels the compressor is suitable for. For passenger cars this parameter is 3 atmospheres, for trucks 10.


From the cigarette lighter, hooked directly to the battery or independent power from your own battery. It is easiest to use the connection through the cigarette lighter, but you need to consider the power of the compressor and the rated current of the fuse on the cigarette lighter so as not to burn it. Connection to the battery in this regard is more reliable, but not always comfotrno, in some models, the battery is hidden too far away, and of course this connection will not like women.

Cable length

The cable should be long enough to reach all four points without problem. Believe me, there are models so poorly designed that the cable doesn’t reach the rear wheels.

Another point worth paying attention to. the length of the air hose, if the principle is to have the ability to pump the wheel and not to keep the compressor on its weight if the valve was in the up position

Nipple mount

Comes in two varieties. flag clamp and brass nipple. The first is convenient, but often consists of plastic parts or all plastic, with frequent connections quickly breaks down. The most reliable. all-metal flag clamps or brass nipples.

Tonometer type

Available in analog or digital. The analog ones are cheaper, but not always convenient. On some models, only the scale with atmospheres and half atmospheres can be clearly distinguished, it is quite difficult to see tenths of a fraction on such a scale. And the digital ones are usually more accurate.

How to choose a pneumatic wrench for the garage

All impact wrench models work on the same principle. The tool is supplied with compressed air via a hose connection. Comes from a compressor or fixed air line. High-pressure air drives the rotor of the impact wrench, which is connected to the spindle. The reverse function is designed to reverse the direction of rotation.

Basic types of impact wrenches

Each impact wrench is designed for a specific application. If you choose the right model, the tool will be convenient to reach difficult places, increasing productivity. In terms of performance, air tools are divided into two types:

  • Direct. Impact wrenches look like a gun. Spindle axis parallel to the rotor axis of rotation, thus providing more torque.
  • Impact wrench angle models have a low torque. It has to do with the perpendicular positioning of the spindle axis in relation to the rotor axis of rotation. The tool creates more force, due to which rusty nuts can be unscrewed.

Besides their construction, wrenches differ in their working principle. Or rather, it can be called a function that helps to better cope with troublesome bolts. The tool is divided into two types according to this parameter:

  • Impact wrenches only have torque. The tool is used for assembling and disassembling assemblies with new bolts. No risk of thread breakage due to low torque.
  • A pneumatic impact wrench works on a similar principle, but in addition to the torque, a series of frequent strokes are added. There are long and short wrenches for the different tightening phases. The tool creates the peak impact at the final installation stage, which increases connection reliability or makes problematic parts easier to loosen.

Attention! Each impact wrench has its own thread wrench head. Black bits are suitable for impact tools, but not ordinary bits, because they would break on impact. When choosing a tool with an impact function you should understand that not all of them operate according to the same principle

The impact mechanism differs between different impact wrenches. The most common are distinguished by three types:

When selecting a tool with an impact function, you need to understand that not all of them work on the same principle. The hammer mechanisms differ between the different impact wrenches. The most common ones are distinguished by three types:

choose, compressor, your, impact, wrench
  • Twin hammer in translation means double hammer. The tool develops a high torque when it starts. Two blows occur per spindle revolution. Suitable for high loads.
  • Rocking Dog creates one impact per spindle revolution. When you start, the tool has a medium high-torque output. The mechanism is suitable for medium loads.
  • Single ratchet represents a ratchet mechanism. Used in angle wrenches. A mechanism suitable for light loads.
Read more:  How to set the ignition on an agro walk-behind tractor

Do not use the impact wrench for anything other than its intended use. Failure of the working mechanism or tearing of the fastener threads can occur.

choose, compressor, your, impact, wrench


This parameter is considered the main one, because this is the power of the pneumatic tool. The measurement is calculated in Newtons/meter. Higher torque requires a more powerful compressor. This parameter requires special attention. If you buy a weak impact wrench, it will not cope with rusty nuts. A new fastener will tighten only slightly. It will spontaneously come apart in the process. Do not select a tool with a large margin either. It will break threads from overstressing.

Important! An impact wrench with a torque of 1,500 to 3,000 lb. is suitable for work on large fasteners. Nm

To remove and mount passenger car wheels, you only need 100 to 700 Nm of torque.

Spindle size

Often called the square drive unit. It is used to put working heads on it. The more powerful the tool, the larger the spindle. parameters are shown in the table.

Compatibility with the compressor

Each impact wrench is designed for a specific air consumption. In addition the tool needs to create the right working pressure. Compatibility with a compressor is considered successful if it generates 2 bar more pressure than the impact wrench requires. The capacity should be 20-30% more, otherwise there will not be enough air to work.

Select a compressor that is compatible with the impact wrench in terms of capacity and pressure

Choosing a compressor for your home

Need help choosing the best air compressor for home use? So, now there are many different types of air compressors, and it is difficult for you to determine which type or brand of compressor and for you the best?

In this article, we’ll look at a number of considerations that you need to keep in mind to determine which compressor is best for you. If you will be using it as an industrial, connected to a pneumatic system that works with several pneumatic tools, the tips in this article will help you to make the best decision in what you need in an air compressor.

What productivity you need a compressor for? What you should look at is the pumping capacity in the specifications of the various models available to determine the size you need. If you intend to use it regularly with tools that need a lot of air to keep them running, then you need models with an inflation capacity of at least 10 kg/yr.

To determine what kind of compressor you need, you need to know the required air flow for the tool. Choose a compressor with 1.5 times the power needed for the tool. For example, if you are going to run an impact wrench that needs 10 kg/year to work properly, then you should choose an air compressor that is capable of generating 15 kg/year of air at 1 atm.

What it will be used for? If you only need a compressor for home use to perform small tasks such as inflating tires and sometimes creating pressure for inflatable equipment or running pneumatic tools that only require short bursts of air, then choose one of the small portable models available.

Of course, if you want to use it for large jobs around your house, especially if you are going to do the work by moving it, such as running pneumatic tools or paint sprayers, then you need to choose an electric one that can generate an air volume of 150 kg/year.

How often will you use? If you intend to use it occasionally, choose models with an electric motor, at least with a 220V motor voltage that can be plugged into a standard outlet. But if you are going to use it often, at least about 4 times a month, choose compressors with good oil lubrication, a cast-iron pump, direct motor drive and at least a 30-liter air tank.

For you who intend to use the compressor more than 4 times every month, choose a model with an electric motor and a belt-driven iron pump. Be prepared for proper wiring. They have at least a 380V output, so make sure there is proper power.

How it will work? You have several options when it comes to how your compressor works. There are some that work directly with electricity or those that run on fuel. If you intend to use around the house or in the garage, a workshop powered by electricity is most appropriate. However, if you want to use it in the field or in the garden, the model with an internal combustion engine would be better.

Both types are reliable and can work with a variety of tools. Of course, which is the best brand of air compressor, model and type really comes down to a personal choice.

How much are you willing to spend? In this tough economy, we are all looking for ways to save money and buy a good quality air compressor that will last as long as possible. Making your choice and taking the advice from this article, you should better understand how to choose an air compressor that will best meet your needs. Remember the saying “you get what you pay for.

How to choose an automotive compressor? Instructions.

An overview of popular electric compressor models

Working pressure

No less important parameter. operating pressure. It indicates how much air must be compressed in order to work properly. It is necessary to consider the technical capabilities of the compressor itself. Its working pressure and the tool should be about the same. Measured in barre or atmospheres.

With a lack of this indicator, the equipment will work poorly or will not work at all. And if there is too much pressure you can damage the air tool.

This characteristic is often compared to the electrical voltage in the mains. If the tool is designed for 220 watts, at a low voltage, it will not start, and at a high voltage. it can burn out.

Therefore, when selecting equipment to a compressor, you need to consider all the parameters. This is the only way to ensure that they work reliably and properly over the long term.

Wrench compressor types and applications

A compressor for a screwdriver or other pneumatic tool must always be fit for the purpose of its future use. Depending on the purpose there are the following types:

    The Impact wrench is ideal for your garage. The compact model is suitable for servicing your car.

  • Oil-free piston compressors. mounting fences, fences or building fronts are just a few of the applications they are good for Are built for long, hard work. A compressor is designed for long service life because of its motor cooling system.
  • Screw-type units. precise and meticulous work is their forte. Compressors like these give out purified air and high performances.

When choosing a wrench compressor it’s important to consider

  • Torque reading.
  • Idle speed (selected according to the intensity of the work required).
  • Fit size (to match the socket of the impact wrench).
  • The length of the tool shaft.
  • Air consumption (depending on the compressor available).
  • machine weight.
  • Type of body.

Another indicator that you should pay attention to when buying a compressor is the capacity, that is, the amount of air that the machine is able to compress for 1 minute. It determines how effectively the pneumatic tool will work.

We recommend choosing models that have twice the capacity of a socket wrench. If the tool needs 100 liters of compressed air to operate, the compressor must deliver about 200 liters.

It is also important if the compressor will have a cooling element. The body gets hot during the compression process, and the tool may need a break. The availability of a cooling system allows the compressor to run for long periods without resting.

Have questions when choosing a compressor for the nutrunner? Contact the consultants of the online store “Kupi na dacha” by phone:

Read more:  Chinese Cordless Screwdriver Which Is Better

What is it

First, let’s understand what the product is. This is a special tool that has a non-broad specialization, small implementation abilities in the home.

With its help you can perform some specific technological operations. to screw, unscrew threaded and bolt connections: nuts, bolts, threaded anchors, which is fundamental for garage repair work.

Ease of use

For constant use of the acquired tool in the garage should be checked in advance how it is comfortable. That operation would not cause difficulties, the weight of equipment should be small. The weight of the impact wrench is influenced by additional parts, including moving seals, pusher, joints, and others. Lightweight construction with little weight and enough resources to perform everyday household tasks as comfortably as possible in operation.

For passenger cars

As the need to use the impact wrench to repair cars, requirements are not as high as for trucks. Small torque value is 250 Nm. For consistent use, tools with 600 Nm torque and M600 fasteners are available.

If you plan to repair a passenger car in an open area or in a garage, where there is no possibility to connect to the power grid, it is worth choosing a self-contained variety. Rechargeable battery-operated equipment has no cords, which provides mobility and simplifies daily operations.

Since the standard capacity of the battery is not enough for a long time, the standalone model is not suitable for continuous operation and works requiring a huge amount of time.

Construction features

Different models of equipment have personal pluses and design features. Namely:

  • Reverse rotation for unscrewing the nuts. Most of the standard varieties have only screwing possibility due to lack of function of reverse rotation.
  • A tightening regulator which automatically indicates the torque at which the element is screwed on sufficiently within close tolerances.
  • Angle head, which makes it possible to fix bolts and nuts on the sides. Angle models are characterized by small size and lowest tightening torque.

How to choose a compressor for the wrench

While choosing a compressor for a impact wrench, you need to clarify the pneumatic wrench. An important technical feature is the torque. The size of the torque has a particular impact on the nature of those operations, which can be performed with a given wrench, as well as temporarily perform them.

It goes without saying that the higher the torque, the tighter you can tighten the screw joint (or unscrew a “stuck” nut). But from a slightly different angle, the implementation of an excessively massive wrench leads to damage of the thread connection (thread breakage).

That is why it is important for the torque to be appropriate for the task in hand.

If we give a numerical estimation of the torque characteristics, then with pneumatic nutrunners it ranges from several tens to several thousand Nm. An impact wrench designed for household and semi-professional tasks must have a torque value between 200 Nm and 600 Nm. For tougher jobs you need wrenches with a torque of 1000 Nm or more.

The torque value also has a decisive influence on the next important thing to know about the impact wrench. the square footage of the spindle. Here it is all very simple: the higher the torque, the more simply the size of the square.

The standard range of shank squares is measured in inches. Spindles ½, ¾ and 1 inch are more common.

Typically, for domestic and semi-professional tasks wrenches are used with a ½ inch square, in the industry with a ¾ and 1 inch square.

it is possible to consider the size of the spindle square and at the same time.

According to statements of wrench manufacturers, the size of the square is related to the size of the nut (bolt head) which needs to be unscrewed / tightened:. if the size of the nut “turnkey” from 10 to 21 mm, the wrench with a ½” square is suitable;. if the size of the nut “turnkey” from 24 to 36 mm, the wrench with a ¾” square is suitable;

The third main technical feature of the impact wrench is the air consumption. This is furthermore to a large extent related to torque: The higher the torque, the higher the air consumption. Wrenches with a ½-inch square footage have an air flow rate of 150-250 l/min; more powerful wrenches have from 300 l/min and higher.

As an example, here is a summary table of the main technical characteristics of wrenches one of the world’s leading manufacturers of these products.

General Approaches for Selecting a Compressor

After choosing a wrench, proceed to choosing a compressor. The compressor that will be connected to

An impact wrench, must comply with two requirements

How to choose a compressor and impact wrench for your garage

A short video on how to choose the right compressor for a garage or service. Impact wrench

A compressor, impact wrench, etc.д

my new acquisitions.Perhaps for all of these tools later I will make a more complete review when.- The compressor, impact wrench, etc. have to provide the required working pressure of the compressed air;

The standard working pressure required for most wrenches on the market is 6.2-6.5 bar. Therefore, the compressor to be used for work must have a maximum working pressure of 10 bar (or, in other words, to work in the pressure range of 8-10 bar).

How to choose a compressor by capacity? The air consumption of your impact wrench is written on the data sheet. In practice, however, the impact wrench is not used all the time, but only intermittently.

That’s why every pneumatic tool (including the impact wrench) has its own so-called utilization factor. In our case, it is 0.2 to 0.25.

Therefore, if the manual for the impact wrench indicates that its air consumption is 300 l/min, then 60 to 75 l/min should be taken into account for the actual calculations.

If more than one impact wrench is planned, the probability of their simultaneous operation must also be taken into account. This is determined by the simultaneity factor of the equipment, the values of which are given in the table below.

Thus, the previously calculated value of the total consumption of compressed air need to be multiplied by the corresponding synchronism factor. And on the basis of the resulting value choose a compressor.

The further order of choosing a compressor is exactly the same as when choosing it for any other equipment. There are two types of compressors: piston and screw compressors. If the value of air flow up to 1000-1200 l / min, you can use a piston compressor, if higher, it is better to use a screw compressor.

On the other hand, the choice of compressor type depends on the nature of work: if it is a one- or two-shift operation, a piston compressor is quite suitable; if the mode of operation is round the clock, a screw compressor is required.

Questions about the practical use of the impact wrench

The first question that arises most often, what quality of compressed air is needed to operate the pneumatic nutrunner? If it is possible to use dry compressed air to power the impact wrench in the production process, then the choice of compressed air quality is no longer an issue

Compressed air is excellent. If there is no such a possibility, you can do without a refrigeration dryer. In this case it is enough to install in the pneumatic line of the filter with a moisture-oil separator with built-in pressure regulator and lubricator. A moisture-oil separator filter will remove moisture, a regulator will provide the necessary compressed air pressure and a lubricator will lubricate the tensioner.

By the way, if there is an opportunity to provide dry compressed air to the production facility the air treatment unit should be installed in front of the wrench anyway. In this case it includes a pressure regulator and lubricator.

The next question is about installing an air treatment unit in the pneumatic line. Whatever the geometry of the pneumatic line, there are two basic ways to install air preparation units in it: above the main tube and below the main tube.