You have to be careful with this stuff. There are many types of hose and fittings. Some fittings made for other types hoses, and they only have a part no. so unless you look it up, the hose AND the fittings, you can end up with a mismatch and leaks. Some hose is a nominal call out size. One popular multi purpose "single braid" hydraulic/ oil / air hose we used to deal with was just slang referred to as "Aeroquip" as they were the major brand in the area. It was used on a lot of systems on heavy trucks and equipment around here
The point is, that stuff if you had a no6 fitting and hose, was closer to 5/16 than 3/8. In other words it averages about a 16th smaller than the call-out part number.
The point? BE CAREFUL and make sure your fittings and hose ends and hose is all comatible
AND YOU DO KNOW?? right? the difference between AN/ JIC which is 37* flare, and SAE which is 45? Most common 45 flare (SAE) is brass, but not always. You occasionally see SAE in most any and same material as AN/ JIC