Take a deep breath. Relax. We are going to try and untangle some terms that get thrown around a lot in the hydraulic industry with reckless abandon (and sometimes used incorrectly). Inconceivable! Nay, it is not.

Over the years many segments of industry have coined their own terms or colloquial verbiage when it comes to hydraulic fittings and configurations. This post is designed to teach you what the fitting actually is, what engineers call it, what shade tree mechanics call it, what people who are just wrong call it, and what your conspiracy theory having uncle calls it (beware the lizard people!). With all that in mind, strap yourself in, this might get bumpy.

Let’s examine some of the most common ends and what their abbreviations stand for, and what dimensional attributes they have.

JIC

JIC actually stands for Joint Industry Council, and is the jealous cousin of SAE fittings. JIC was derived originally from another term you may hear, AN thread. It’s thread pitch is the same as an SAE 45 degree fittings, but it’s cone seat is 37.5 degree. How on earth do you get half a degree? No one knows, but it’s important.

This type of hydraulic fitting is typically used in high pressure applications, as well as when test ports are needed. JIC threads make up a large percentage of what you will see on industrial machinery. To place an exact number on the market use of this style of fittings is impossible, but it sure is a lot.
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You will hear JIC called – AN, FLARE, CONE SEAT, POINTY LOOKIN FITTING

AN

AN stands for Army-Navy. It was developed as a thread pitch by the US military as a means to standardize the hoses and mating surfaces on machines that both the Army and Navy were using around the time of WWII. JIC has since replaced these fittings in most applications. It actually IS the same fittings, except JIC is not manufactured to the same exacting tolerances as AN fittings are.

Think of AN as the straight laced Step dad and JIC as that saucy aunt who lets you smoke a cigarette with her. The most common time you will see hydraulic AN fittings is when they are aluminum, anodized (usually red, blue, or black) and in a reusable style in the high performance auto racing industry. It’s called visual horsepower. Didn’t you learn anything from Fast and the Furious? Sheesh.
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You will hear AN called – CONE SEAT, FLARE, RACING FLARE

SAE

SAE stands for Society of Automotive Engineers, and this organization basically wrote the book (literally) on what is standard in Hydraulics. With exception, it’s essentially the reference and generally accepted guide to specs and tolerances.

I might lose you here, so pay attention- SAE has a flare fitting which is 45 degree cone seat, where the sealing action happens metal to metal on the cone as its tightened, just like JIC. You will typically see 45 degree flared fittings in brass applications and usually its air that is being conveyed as opposed to hydraulic, but not always.

SAE also has a straight thread fitting with an O-Ring, referred to as an O-ring Boss. The sealing action happens between the O-ring and a bevel, or chamfer on the female threads. YES – you can thread a JIC into an SAE. However, this will cause leaks and premature wear at the least. Furthermore, you can thread a JIC into an SAE 45 with the exception of 3/8 and ¾. And before you brain turns to hydraulic fluid, let’s move on.
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You will hear SAE called – BOSS, O-Ring, STRAIGHT THREAD
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You will hear SAE 45 called – Flare, BIG 6 (Big 6 because the 3/8 or -06 is “bigger” than the 3/8 JIC)

NPT

National Pipe Thread. There it is. I can see the threads in my mind as an eagle holding an American flag and an AR-15 soars in the horizon. This is probably the most common thread here in God’s country along with JIC. Some call out this abbreviation as National Pipe Taper, which is true in name as all NPT thread is tapered.
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You will hear NPT called – PIPE, MNPT (male), FNPT (female), STANDARD (it’s not, nothing is)

BSPP & BSPT

BSPP stands for British Standard Pipe Parallel, and BSPT stands for British Standard Pipe Tapered. BSPP threads are common in Australia and other places where those darn redcoats once had dominion.
Which is basically everywhere, but it’s more concentrated in the old commonwealth countries. This one gets confusing to some because the thread callout is based off a nominal size. For the sake of this post,
know that they are very similar to NPT but not close enough, and BSPP and BSPT are not interchangeable, though they have the same thread pitch.
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You will hear BSP fittings called – BRITISH, JAPANESE (seriously), BP, G, Rp, R, Rc

JIS

JIS stands for Japanese Industrial Standard and this is where things get complicated in the hydraulic world. As if we didn’t have enough to sort out, JIS fittings have a 30 degree cone seat with threads identical to a BSPT.
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You will hear JIS called – “It’s like a weird import thread or something”
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We could carry on, but the point of this is to explain some of the differences between the most common threads you may run across in hydraulics. Honorable mentions include, but are not limited to, Komatsu, Kobelco, Metric DIN, and Face Seal (this one’s actually a good one to cover. More on that later).

Understand that some of these fittings are very similar dimensionally speaking, and it can be difficult to identify what you are looking at. The safest bet is to bring your hose or fitting in question to American
Hose and Supply. Our trained technicians are happy to break down what it is you have, and what you need to get going again. Hopefully this guide helps distinguish between some of these different types of hydraulic threads. Now go get ‘em tiger!

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