This connection is commonly used in refrigeration, automotive and truck piping applications. Both the male and female connectors have a 45° seat and are most frequently made of brass. When the fittings are mated and the threads are engaged, the seal takes place between the male flare and the female cone seat. SAE J512 45° and SAE J514 37°(JIC) have some similarities. In the -2, -3, -4, -5, -8 and -10 sizes, the threads are the same but the angle of the flares are different, so extra care should be taken when identifying these fittings.