-Joint Industry Council fittings, defined by SAE J514, are compression fittings machined with a 37 degree flare seating surface and parallel threads. They are commonly manufactured in nickel alloys, brass, carbon & stainless steel.

-JIC Fitting hydraulic connections are common in most fluid power systems. Both male and female components have 37° seats. The seal is made by establishing contact between the male flared and the female coned seat. This is considered a mechanical connection. There are three components that make a tubing assembly; fitting, flare nut and sleeve.

-National pipe tapered threads have been widely used for over 100 years. NPT is a U.S. standard for tapered threads used on pipes and fittings. They are used to effectively seal pipes for fluid and gas transfer. The nominal pipe size can be identified by physically measuring the thread diameter, then subtracting 1/4″.
-They are available in iron or brass for low-pressure applications and carbon steel and stainless steel for high-pressure.

-As the name implies, ORFS, or (O-ring Face Seal) fittings incorporate an O-ring at the face of the fitting. Made to SAE J1453 standard, ORFS connections are commonly manufactured in carbon, nickel plated carbon & Stainless steel and typically use Buna-N or Viton, 90 Durometer O-rings that seat into a groove in the face of the fitting. This is known as an elastomeric seal.

-The seal is created when the o-ring compresses between the o-ring face of the fitting and flat face of the mating ORFS fitting or the formed tube. When the connection is tightened the O-ring compresses against a flat face of mating fitting or tube.

-SAE Straight Thread O-ring Boss fittings, incorporate a port connection as recommended by the National Fire Protection Association (N.F.P.A.) for leak prevention in medium and high pressure hydraulic systems. ORB connections are commonly manufactured in carbon, nickel plated carbon & stainless steel and typically use Buna-N or Viton, 90 Durometer O-rings. The male connection is a straight UNF thread with an O-ring. The female port has a straight thread and a machined surface to provide a smooth, flat, accurately located surface (minimum spotface), along with a chamfer where the O-ring seats. The seal is created when the O-ring is compressed into the chamfer when mating the male and female connection providing a leak-tight seal.

-British Standard Pipe (BSP) is one of the most common fitting styles used worldwide. BSP is used on some of the world’s most recognized machinery such as Case IH, JCB, New Holland, and John Deere. British Standard Pipe threads are available in two versions, British Standard Parallel Threads (BSPP) and British Standard Pipe Taper (BSPT).

-BSPP is very similar in appearance to American National Pipe Straight Mechanical (NPSM) fitting but the two are NOT interchangeable. While both NPSM and BSPP seal on the cone seat of the male / tapered nose of the female, the threads are different in most sizes.

-BSPT is also very similar in appearance to American National Pipe Taper (Fuel) (NPT(F)) adapters but just like the BSPP/NPSM fitting connection mentioned earlier, the BSPT/NPT(F) are NOT interchangeable due to subtle differences in size and thread form.

-Japanese Industrial Standard JIS 30° Flare uses the same thread size and form as the British Standard Pipe family of fittings. The JIS 30° Flare is very similar in appearance to the North American JIC 37° fitting (SAE J514) but is NOT interchangeable due to the difference in the sealing angle and the thread form and size. The JIS 30° fitting connection features a 30° chamfered seat angle on the leading end of the male fitting that fits snugly against the 30° angle machined into the bottom of the female fitting forming a metal-to-metal seal when tightened.

-Note: the thread sizes are often expressed as fractional dimensions preceeded by the letters “G” or “R”, where “G” represents a parallel thread and “R” represents a tapered thread. Example: BSPT 5/8-14 can be designated by R 5/8 and BSP 1/16-28 can be designated by G 1/16.

-Metric hydraulic adapter fittings resemble British and SAE (American) fittings in many ways.

-One of the most popular Metric fitting styles is the ISO 9974. ISO 9974 fittings are commonly used in hydraulic port applications. ISO 9974 fittings resemble SAE O-ring boss fittings and British Standard Parallel Pipe (BSPP) ISO 1179 fittings, the difference being metric threads. ISO 9974 fittings use a captive or retained seal at the base of the threads that mates to a seat surface on the female fitting or ported surface on a hydraulic cylinder or valve.

-Metric port fittings ISO 6149 also are very similar to ISO 9974 port fittings except they use a non-retained O-ring same as the SAE O-ring Boss Fittings.

-Another popular Metric fitting series is the DIN tube fittings. DIN tube fittings have a 24° chamfered seat on the inside of the male fitting that identifies the fitting as DIN, that 24° seat is where the seal takes place when joining a DIN male to a DIN female fitting. DIN fittings employ an identification system used by most manufacturers, this system combines the tube O.D. size and the tube Series, for example, a fitting that is 8mm and heavy duty would be marked “S08”.

DIN designations:
LL = Extra Light Duty
L = Light Duty
S= Heavy Duty

-Metric threads are called out using the distance between two threads as the Thread Pitch, this is different than American SAE and British Standard threads that are designated by Threads per Inch.
There are three common thread pitches used on all Metric DIN fittings, 1.0mm, 1.5mm & 2.0mm pitches.