I know that fittings and threads often leave people scratching their heads trying to figure them out. I came across a somewhat quick reference that I printed out and am going to laminate it for my shop. I also had good luck dealing with the company who produced the reference. They have wall charts that are reasonably priced as well, but I think keeping a copy of this in your shop may help figure out what you need. That's all Folks
A set of thread gauges and a caliper, along with that info will solve 90+% of your applications. Remember that JIC and AN are basically the same, except AN is made of aluminum.