Steel Adapter, 9/16-18 Male JIC 37 deg Flare To 1/2-20 Male JIC 37 deg Flare, Straight

That's what this adapter does. One end is 9/16-18 male JIC 37-degree flare, the other is 1/2-20 male JIC 37-degree flare, straight configuration. Both ends use the same SAE 37-degree seating angle, so as long as your mating fittings are female JIC on both sides, you've got a match. It's a union-style adapter, meaning it connects two separate female ends rather than threading into a port on equipment.

Primarily, this union adapter is used in hydraulic, instrumentation, and chemical processing systems.

For connecting two SAE 37 degree JIC flare ends with those thread sizes, that’s exactly what this union adapter is set up to do. It is a straight steel adapter with a 9/16-18 male JIC 37 degree flare on one end and a 1/2-20 male JIC 37 degree flare on the other.