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What size air compressor do I need for an impact wrench? Although air compressors come in different sizes, the size doesn’t usually determine the compressor’s ability to power your impact wrench. I’ll show you how to calculate the air requirements of your impact wrench in order to find the right air compressor.
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What Size Air Compressor Do I Need for an Impact Wrench?
Generally speaking, you need an air compressor that is 1.5 times higher than the minimum requirement of the impact wrench. So, with the average ½” impact wrench needing 5 CFM at 90 PSI, you would want an air compressor that is rated at 7.5CFM.
Alternatively, a 1″ impact wrench will need an air compressor with 10 CFM at 90 PSI, while a ⅜” impact wrench will only need an air compressor with 3 CFM at 90 PSI.
Most impact wrenches have the ½” drive that you will most likely be looking at about 4 to 5 CFM at 90 PSI.
However, there are some other factors that will determine the size of the air compressor you’ll need. These include the type of project, type of impact wrench, the power source, the amount of space you have, and where you will be using it.
How to Calculate Air Compressor Tank Size and Impact Wrench Air Requirements
There are two other very important determinants of your air compressor’s size. These include:
- Impact wrench air requirements
- Air compressor tank size
Impact Wrench Drive Size
Impact wrenches come in a lot of sizes, but the four most common sizes are:
- ⅜”
- ½”
- ¾”
- 1″
This is important because the larger the impact wrench, the more air it needs. Airflow is measured in Cubic Feet per Minute (CFM), measured at 90 Pounds Per Square Inch (PSI).
How to Calculate the Amount of Airflow Your Impact Wrench Needs
Since the recommended CFM of the impact wrench is set by the manufacturer, I only need to calculate the minimum CFM rating of the air compressor. To do this, you multiply the impact wrench’s CFM by 1.5.
For example, if your impact wrench has 4CFM, the Air Compressor CFM = 1.5 x 4CFM which equals at least 6CFM of airflow from the compressor.
Here are the CFM ratings for the common impact wrench sizes:
- ⅜”: 3 CFM @ 90 psi
- ½”: 5 CFM @ 90 psi
- ¾”: 7 CFM @ 90 psi
- 1″: 10 CFM @ 90 psi
This means that you would need the following sized air compressor for each of the common impact wrench sizes:
- ⅜”: 4.5 CFM @ 90 psi
- ½”: 7.5 CFM @ 90 psi
- ¾”: 10.5 CFM @ 90 psi
- 1″: 15 CFM @ 90 psi
How to Calculate the Size of Air Compressor Tank Needed
Now that you know how much CFM the air compressor needs to produce in order to power your impact wrench, it’s time to determine the size of the tank that can support that airflow.
Air compressor tanks can go up to more than 60 gallons. The bigger the tank, the longer the compressor will power the impact wrench before having to produce more compressed air. Since the impact wrench won’t require a continuous flow of air like sanders or power tools such as grinders, you’ll probably be looking at a smaller tank.
In order to find the minimum tank size, simply multiply your impact wrench recommended CP by 6. For instance, going with my previous example, if you have an impact wrench with 4CFM, the size should be:
4CFM x 6 = at least 24- liter air compressor tank. This is simply an estimation and I recommend that you go with a slightly bigger tank to be on the safe side.
Other Factors to Determine the Size Air Compressor You Need
There is no one-size-fits-all air compressor for every impact wrench. Below are other factors that will help you determine which air compressor is good for your impact wrench.
Type of Project
The type of project you are doing will no doubt determine the size of the air compressor to power the impact wrench. High-torque tasks like large construction projects, car repair or assembly projects will need a stronger air compressor such as the California Air Tools 8010 compressor.
Simple tasks like regular maintenance around the home or DIY projects will do with a smaller air compressor.
Size of Impact Wrench
Depending on the size of the impact wrench you have, the size of the compressor will also vary.
That means a 1-inch drive will need an air compressor with a bigger tank and more airflow compared to a ½” inch and ¼” inch drive.
Amount of Space
If you are not doing projects that require high-torque impact wrenches, you might want to consider the amount of storage space you have. In this case, if you have limited space, you might want to go with something smaller like a pancake air compressor.
On the other hand, if you have plenty of space and need something with a bigger tank, you can go with a bigger compressor. However, keep in mind that size doesn’t always determine the air output of a compressor. For instance, you might get a compact air compressor with higher air output than a larger air compressor.
Your Workplace
As insignificant as this might seem, the place you will be working from might determine the size of the air compressor you need. For instance, if you only work in one place like a garage, a big air compressor will be fine.
However, if you move from one place to another, a smaller and lighter air compressor that’s easy to move could be better. Additionally, there are other stationary workplaces that will naturally determine whether you need a big or small air compressor.
Frequently Asked Questions
Is the Size of the Air Compressor Important?
Yes, the size of an air compressor is important as it determines the amount of air it can deliver, which affects its performance in various applications. If the compressor is too small, it will not be able to keep up with demand, and if it is too large, it will be inefficient and waste energy.
- Power rating in Horsepower (HP)
- CFM – Amount of airflow from the air compressor
- Pounds per Square Inch (PSI) – Pressure of airflow
- Tank size in liters
This information is usually indicated on the user manual or on a sticker on the air compressor.
Will a 100 PSI Air Compressor Run an Impact Wrench?
Yes, a 100 PSI air compressor can run an impact wrench, but the performance will depend on the specific requirements of the impact wrench and the amount of air it needs to operate effectively. Most impact wrenches require at least 90 PSI to function, and a 100 PSI air compressor is on the larger side.
Will a 30 Gallon Air Compressor Run an Impact Wrench?
A 30-gallon air compressor with a high-quality pump and a powerful motor should be able to handle a ½” impact wrench with 5 CFM at 90 PSI.
Conclusion
While the size of the air compressor needed to power a given impact wrench is still important, there are other factors that will determine if the compressor is a good fit for you. These include horsepower, CFM, and PSI. So it is important that you keep these things in mind while shopping around for an air compressor.
