What size air fitting do I need for my tool?

Tools should always use a male air fitting which allows the air to discharge from the tool when the air hose is removed.  As a rule of thumb, framing tools use 3/8” air fittings and smaller tools such as trim nailers use 1/4” air fittings. The tool will be threaded for either a 3/8” N.P.T or a ¼” N.P.T. air fitting.