Air tool buying guide

Air tools, or pneumatic tools, are lighter than their corded or battery-operated counterparts. The basic design of these tools means that their parts are less likely to break down and their performance is more stable – provided that you choose the right size of compressor to power them.

Some tools, such as air nail guns, offer certain features that are exclusive to this power source such as quick firing rates. Other tools are simply more efficient when powered by compressed air rather than mains power or batteries. Finally, there are tools that only function using this technology.

Most common power tools can be powered by compressed air as well as a few more specialist tools such as jacks, rivet guns and shears. The most popular air tools are as follows:

• drills;

• saws;

• rotary hammers;

• impact wrenches;

• angle grinders;

• nail and staple guns;

• paint sprayers;

• abrasive blasters.

To ensure your air tools are used correctly, you need to pay close attention to:

• the operating pressure of the tool you are using (in bar or PSI);

• the air flow required in cubic feet per minute (CFM);

It is essential that the air compressor can handle the air requirements of each tool to ensure they can work as efficiently as possible. This includes tools like impact wrenches, drills, paint sprayers, angle grinders and blasting machines.

The tank capacity determines how long the air compressor can be used before the motor has to run once more and stock the tank with compressed air. A minimum tank capacity of 50 litres is required for most tools.

Additionally, the diameter of your air hoses will impact the air flow of your tools. Be sure to follow the recommendations of each tool to ensure efficient performance. Finally, be sure to use the correct connector sizes.

An air compressor is powered by a pump unit which is made up of an electric motor or petrol or diesel engine and a cylinder equipped with a piston. This assembly compresses the air before sending it into an airtight tank which is kept within a pre-set pressure range. This tank can vary in volume.

The pump has the sole purpose of compressing air while the tank is there to store it. The pump stops when the pressure limit of the tank has been reached and will fire up again once the pressure drops below a certain level. This level depends on the size of the compressor and pump unit, and the limit set by the manufacturer. The compressed air generated is then used to power air tools. 

Air tool CFM rating

The most important feature of an air compressor is the amount of air flow it can provide. Air flow is measured in cubic feet per minute or CFM. The air flow of an air compressor depends on the volume of the tank and how fast the tank can be filled which is determined by the efficiency of the pump unit. Small electric portable air compressors will have a small tank capacity of around 2 to 6 litres meaning they usually have to run continuously. These air compressors are only able to handle small jobs. Choosing the right air compressor all comes down to analysing your needs in terms of air flow and pressure.

It is fairly straightforward to ensure your air compressor is equipped to handle your tools, but you do need to account for a safety margin.

Add up all the air requirements of your air tools (paint sprayers, airbrushes, etc.) and multiply the result by 1.5. This figure will indicate the CFM rating you need from your air compressor. Be sure you are adding up CFM ratings as some air tools may indicate air flow in cubic metres per hour.

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