AN, AND, MS, AS
AN / AND fittings have a 37° flare angle and use a class 3A/3B thread, which is a close tolerance, radiused root thread. These fittings have traditionally been available in aluminum, carbon steel, stainless steel, and titanium.
AN / AND fittings remain in prevalent use today, and they may alternatively be designated with an MS number, which are generally directly cross-referenced replacement fittings (functionally equivalent). For instance, an AN815 is equivalent to an MS24392. MS, however, is a very broad standard covering all kinds of hardware, and is not limited to AN fluid couplings.
The AN and MS designations for many fittings are being superceded with AS (Aerospace Standard).
In general, there appears to be a trend away from flared tubing in favor of compression type fittings, probably due to the fact that flares require greater special attention to craftsmanship (and more time) in assembly
JIC, SAE 37°, ISO 8434, Parker Triple-Lok
When someone says it's a JIC fitting, this is generally what they are talking about.
- This fitting is the general industrial adaptation of the AN fitting.
- These fittings have a 37° flare angle and use a class 2A/2B thread, which is a standard tolerance industrial thread with normal trapezoidal root truncation.
- These fittings have traditionally been available in carbon steel, stainless steel, and brass. Some of these fittings may conform to MIL-F-18866 and/or SAE-J514.