Usage of three different types of Pneumatic Fitting Pneumatic Fitting is a type of quick coupling widely used in air configuration and pneumatic tools to connect or disconnect pipes without any tools. It is mainly used to connect air compressors, air screwdrivers, impact wrenches, air pipes, grinders, air drills, and many other pneumatic tools. I think not many people know how to use Pneumatic Fitting, today I will introduce the types of Pneumatic Fitting and how it should be used. Here are some answers.