A. The 15/16" - 16 thread flare fitting is used strictly for natural and propane flexible gas connectors and not for water or with fittings used in automobiles. Up until the 1980's, 5/8" O.D. SAE (Society of Automotive Engineer) standardized flare fittings were used for natural gas and propane flexible gas connections.
5/8" O.D. SAE Flare fittings were too close in size to 1/2" iron pipe size (IPS) fittings and pipe nipples. Because of this, 1/2" IPS couplings were often being used to connect to 5/8" O.D. SAE Flare fittings and IPS nipples into flexible gas connectors which then would not properly seal causing a small gas leak. To alleviate this type of safety issue, the American gas industry implemented the 15/16" threaded flare fitting with fine threads (16 threads per inch) to be used on 5/8" O.D. (outside diameter) tubing.
The flare fittings we offer are SAE 45� flare with the exception of the 15/16"-16 gas flare fittings. The 15/16"-16 are 45� flare, but are not SAE fittings".