True "AN" fittings are used in the Aerospace and Military world. The thread class is different than std hyd fittings.

Example: -4 thread in the aerospace world is a 7/16-20 UNJF-3A and the industrial variant is 7/16-20UNJF-2A. The two don't 100% interchange and you can seize or gall the fittings by mixing the two types up. If using "true" AN fittings.

The fittings being pawned off as AN by the automotive world are not the "real deal." They use AN as a descriptor, just as Kleenex is used to describe any nose tissue to almost every one on here. Simply a JIC 37deg flare. Easier to use the bastardized AN label. They are cheap aluminum forgings that get about a 4000% markup when they get passed on to Joe racer being billed as AN.

If you don't need the bling of red or blue aluminum or the small weight savings they offer, then start shopping industrial hyd fitings and save some $$$$. However, there are times that the expensive stuff is needed because the std hyd world does not have the connection you need.

Same goes for hose. Use PTFE lined for fuel and 100R5 for trans, power steering lines, and oil lines.

Also, the true AN fittings that Stratoflex sells are sourced and supplied to Stratoflex by me (well...at least the company I work for). They don't mfg their own...hardly any major fitting mfg makes their own any more.