What size of air compressor do I need for Impact Wrench?

Do you have an impact wrench? Or you’re going to purchase one for a home project or workshop. If you are wondering about the size of the air compressor, you need to run your impact wrench. Don’t worry!! This article will guide you in selecting the right size of the air compressor. An impact wrench is proper where high torque output is required. What size air compressor do I need for an impact wrench? It is a common question. I am going to answer this question. Please, follow the article.

An air impact wrench needs a particular size of air compressor to work. Finding the perfect size of air compressor for the specific impact wrench is a complicated process. In this article, I will help you find the air compressor size for your impact wrench.

What is an Impact wrench? 

An impact wrench is a tool we use to tighten or loosen lug nuts, large bolts, and rusted fasteners. It is designed to deliver high torque output with minimum effort by the user. The impact wrench stores energy in a rotating mass and then gives it abruptly to the output shaft.

what are impact wrenches

Type of Impact Wrench

There are three types of Impact wrench-

Air-operated impact wrench: the most common impact wrench in the industry is the Air operated impact wrench. An air motor and compressed Air provide the rotational air force.

Hydraulic Impact wrench: Hydraulic impact wrenches provide rotational force using hydraulic fluid and a hydraulic motor.

Electric Impact wrench: Electric impact wrenches have become familiar with cordless power tools. This impact driver is good for the minor task, but the air impact wrench obtained more torque and speed.

Use of an Impact wrench

An impact wrench is a ubiquitous tool in many industries. It is widely used in automotive repair, product assembly, heavy equipment maintenance, construction projects, etc. This tool is handy for mechanics. It’s used for loosening or attaching lug nuts. A pneumatic impact wrench is handy for changing tires. Sometimes it helps to assemble large machinery.

What size air compressor do I need for an impact wrench?

Air compressors come in several sizes. But the size of the air compressor you need for an impact wrench generally depends on the size of your impact wrench.

  • The approximate size of air compressor you need for a ½” impact wrench is a 4-5 CFM @90 PSI.
  • For instance, an impact wrench with a 1″ drive will require a 10 CFM @90 PSI, a ½” campaign will need a 4 CFM @90 PSI, and ⅜” will require a 3 CFM @90 PSI.
  • Most of the impact wrench has a ½” drive that you will be looking at about 4 to 5 CFM @90 PSI.

Some other factors will determine the size of the air compressor you want. Such as the type of project you will work on, the kind of impact wrench, the power source, the space you have, and where you will use it.

I will show you the air compressor tank size and impact wrench air requirement.

Impact wrench air requirements and the air compressor tank size are critical determinants for your air compressor size. Let’s see how to calculate the required amount of airflow and the required length of an air compressor tank.  

How to Calculate the Amount of Airflow an Impact Wrench Needs

The airflow measuring unit is cubic feet per minute (CFM). CFM is the mass of Air flowing per minute. The Air pressure measuring unit is pound per square inch (PSI). So, PSI denotes the air pressure.

  • Usually, the CFM of the air compressor should meet the minimum CFM rating of your impact wrench. For that, CFM is generally written compared to the amount of pressure (PSI) required to power an impact wrench. In general, that would be CFM @ 90 PSI. 
  • The manufacturer recommended CFM of the impact wrench. If its producer sets CFM., then the task is to calculate the minimum CFM rating of the air compressor. And for that, you will multiply your impact wrench’s CFM by 1.5.
  • For instance, if your impact wrench has four cubic feet per minute (CFM), then the Air Compressor CFM = 1.5×4 CFM equals a minimum 6CFM of airflow from the compressor.

 

How to calculate the required size of an air compressor tank

An Air compressor is essential to power your impact wrench. Now you know how much CFM an air compressor has to produce. The next step is determining the tank size that will support the airflow. 

Air compressor tanks are available for more than 60 gallons. But for an impact wrench, continuous airflow is not essential like other power tools. So you can go for the smaller tank. To find the minimum tank size, you must multiply the required CFM by 6. For example, for an impact wrench with 4 CFM, the air compressor tank size should be =4CFM× 6=24 liters.

Ideal Air Compressor Size For Different Sizes of Impact Wrench

Impact wrenches are available in several sizes on the market. And every impact wrench has different requirements for an air compressor according to the size.

¼-Inch Impact Wrench

 A ¼-inch impact wrench is the smallest size in impact wrenches. Air compressors delivering 1 to 1 ½ CFM will be enough. But you can use a compressor with higher CFM.

The minimum air pressure for most tools, including this one, is 90 PSI. You’ll need an air compressor that at least features 90 PSI air pressure.  

3/8-Inch Impact Wrench

For a 3/8inch impact wrench, it needs 2x CFM. Using a 3.5 CFM air compressor will be good. You can go for a 2.5CFM, but it’s better to go for a higher CFM than stay on edge.

As for the air pressure, 3/8inch can run on 90 PSI.

½-Inch Impact Wrench

 The most widely used impact wrench is a 1/2inch wrench. It’s a very common tool.

Any compressor from 3.5 CFM to 5 CFM can operate a ½-inch impact wrench easily. If you are buying one then a 4 CFM compressor will be the safest option.

If you choose a higher CFM air compressor; It will give you better service. Regarding air pressure, I will suggest going for at least 90 to 100 PSI.

¾-Inch Impact Wrench

An air compressor requirement for a ¾-inch impact wrench is around 7 CFM. Air pressure of about 90 to 100 PSI is appropriate for a 3/4inch impact wrench.

1-Inch Impact Wrench

1-inch impact wrenches are primarily suitable for construction sites and rare in average houses.

 Wrenches needed air pressure which is from 10 to 16 CFM as well as  90 to 125 PSI.

Will a 3-gallon air compressor run an impact wrench?

The 3-gallon air compressor is famous for home use. These air compressors are marketed for beginner use and are available at meager prices. Will a 3-gallon air compressor run an impact wrench? Some people ask this question. The answer to this question is “No.”

If you think about the air pressure, the 3-gallon air compressors are very weak. This air compressor’s air pressure is around 0.5CFM. But even a tiny impact wrench requires 1 to 1.5CFM to run. The 3-gallon air compressor will not be able to provide enough Air for the impact wrench to maintain the proper speed of work. So, don’t invest in the 3-gallon air compressor.  

Will a 6-gallon air compressor run an impact wrench?

 Yes, but the 6-gallon air compressor is the smallest air compressor that can run an impact wrench. You can work for a few minutes with a 6- gallon air compressor. I’ll not recommend this air compressor for an impact wrench.

Air compressor size chart for Impact wrenches air consumption.

The chart will help you understand impact wrench air consumption according to air compressor size.

The following chart will help you to understand the impact of wrenches’ air consumption according to air compressor size.

Size of Impact wrenchAir consumption in CFMAir pressure in PSI
¼ inch290
⅜ inch390
½ inch 590-100
¾ inch790-100
1 inch10-1590-125

Frequently asked questions

What will the size air compressor run an impact wrench?

You need to select different sizes of air compressors for your different sizes of impact wrenches. The approximate size of air compressor you need for a ½” impact wrench is a 4-5 CFM @90 PSI. For instance, a 1″ impact wrench will require a 10 CFM @90 PSI, a ½”  will require a 4 CFM @90 PSI, and a  ⅜” will require a 3 CFM @90 PSI. Most of the ½” Impact wrench required air pressure of about 4 to 5 CFM @90 PSI.

How many PSI do I need to run an air impact wrench?

The Air pressure measuring unit is pound per square inch. So, PSI denotes the air pressure. The minimum required for an air impact wrench compressor to work correctly is 90PSI. If you need continuous use, the compressor has to serve the demand of the Impact wrenches. But Most air impact wrenches require roughly 100 PSI to operate, but some power-hungry twists demand up to 135 PSI.

Final thought

Now you know the required size of the air compressor to run your pneumatic impact wrench. Remember that Impact wrench air requirements and the air compressor tank size two are essential determinants for your air compressor size. Almost all air tools have specific requirements for both air volume and pressure. In the above, we discuss what size air compressor do you need for the impact wrench?