No sleeve is required to assemble these fittings, which makes for a faster, more convenient installation compared to 37° flared fittings. They are also known as refrigeration and SAE fittings.

Commonly used in high-pressure welding applications, these nipples connect your tank to the inlet of a pressure regulator. One side has a threaded pipe end and the other side has a rounded end that sits inside a threaded nut to make a threaded connection.