Slide a high-pressure hose nipple for compressed gas into one of these nuts to connect a pipe to the inlet of a pressure regulator. They are also known as CGA (Compressed Gas Association) nuts and inlet nuts.

Brass nuts have good corrosion resistance and are softer than 316 stainless steel nuts, so they're easier to thread together. Chrome-plated brass nuts have comparable corrosion and wear resistance to aluminum-plated brass nuts, and have a bright, shiny appearance.

Nuts with a plastic grip can be tightened by hand instead of with a wrench.

Nuts with left-hand threads are identified with a notch.

Note: Nuts have a CGA, BS, or DIN number that corresponds to a specific type of gas. Choose a nut with the same number as your tank and other system components.