Air tools use compressed air to do a number of tasks.

Air can come out of a pneumatic tool with a lot of force, and that can cause damage and injury. So before using an air tool, it's important to check all of its connections are secure, and the hoses are in good condition and not leaking.

It must be lubricated before it's used. This may be done automatically by an in-line oil mister that puts a mist of oil in the air supply.

Or it may need some squirts of light oil into the air inlet fitting. This model also removes moisture from the air before it's fed to the tools.
 

The most common pneumatic tool in an automotive workshop is the air impact wrench. It's sometimes called a rattle gun. It's easy to hear why. Taking the wheels off a car to replace the tires is a typical application for this air tool. It often needs a lot of torque to twist the nuts free.

The rattle gun can be set to spin in either direction, and this valve controls how much torque it applies. It should never be used for finely tightening wheel nuts. There's a real danger of doing them up much too tight. That could cause the bolts to fail and the wheel to shear off the vehicle while it's moving. Another rule with the air impact wrench is to use only these specially hardened impact sockets, extensions and joints.

The sockets are special 6-point types, and these flats can stand the sudden force that the rattle gun provides.
 

This is an air ratchet. It uses the force of compressed air to turn a ratchet drive. It's used on smaller nuts and bolts. Once the nut is loosened, the air ratchet spins it off in a fraction of the time it would take by hand.
 

This is an air chisel. It's useful for driving and cutting. The extra force that's generated by the compressed air makes it more efficient than a hand chisel and hammer.

Just as there are many chisels, there are many bits that fit into the air chisel, depending on the job at hand.
 

This is an air drill. It has some important advantages over the more common electric power drill. With the right attachment, it can drill holes, grind, polish, and clean parts. Unlike the electric drill, it doesn't run the risk of producing sparks. Which is important around flammable liquids or gasoline tanks.

An air drill doesn't trail a live electric cable behind it which could be cut, and cause shock and burns. And an air drill also doesn't get hot with heavy use.
 

This is the simplest air tool. It's a blowgun or air duster. It's really just compressed air by itself, controlled by a lever, or valve.

It's used to blast debris and dirt out of confined spaces. That can be dangerous, so eye-protection must be worn whenever it is used. Noise levels are usually high, so ear protection should also be worn.

It's also dangerous to use it to clean yourself down. Its blast should always be directed away from the user and anyone else working nearby.