JIC 37 andSAE 45 flare fittings is the same seal by metal to metal contact, JIC 37 is the same to SAE J514 and ISO 8434-2 standard fittings, the same SAE standards for the maximum tube wall thickness must be followed before flaring the tube to match the fitting connection.
JIC 37 degree flare union fittings is in most hydraulic systems in high pressure application such hydraulic excavator, loader and tractor etc. SAE 45 degree flare fittings is used in low to medium pressure applications such as military and aerospace equipment.
they doesn't interchangeable into each other.
Jiayuan also can offer JIC 37 flare and SAE 45 flare type fittings.