TruThread P NG 00
Plug gauge NGT

ASME B1.20.3
NGT threads (National Gas Taper) are tapered pipe threads specifically designed for gas applications. They provide a pressure-tight seal without the need for additional sealants when properly threaded into a matching counterpart. This is achieved through a tight fit between the thread surfaces.

NGT threads are commonly used in natural gas, propane, and other gas system connections where sealing integrity and safety are critical. Their tapered design (1:16) allows for a self-sealing connection, reducing the need for additional sealing materials.