JIS and JIC fittings has the same flared tube connectors, but difference as follows:
Standards difference
JIS fittings standard is according to Japanese industry standard such as JIS B8363.
JIC fittings standard is according to SAE J514 and MIL-DTL-18866 standards.
Sealing difference
JIS adapter fittings has 30 degree flare tube connector.
JIC adapter fittings is a type of flare fitting machined with a 37-degree flare seating surface. JIC (Joint Industry Council) fittings are widely used in fuel delivery and fluid power applications, especially where high pressure (up to 10,000 psi) is involved.
Usage difference
JIS hydraulic fittings mainly used in Japanese and Korean heavy equipment such as Komatsu, Kobelco, Hitachi, Kubota etc, often used as hose adapters.
JIC hydraulic fittings mainly used in North America marker, also popular in the worldwide. In manufacturer of heavy equipment such as Caterpillar, John deere etc. Often used as tube connector fittings.
JIS and JIC fitting is not interchangeable to each other. There are two different tubing and hoses connection system.