Mar. 01, 2025
JIC fittings, also known as SAE 37° tube fittings, flared fittings, or SAE J514 fittings, are among the most widely used hydraulic fluid connectors in North America. Their popularity stems from their reliable sealing capabilities and adaptability across various applications.
In this blog, we'll delve into the fundamentals of JIC fittings, discussing their functionality, versatility, and common uses.
Most commonly used as hydraulic fittings in the fluid power industry, JIC (Joint Industry Council) fittings are a type of flare fitting machined with straight threads using a 37° flare seating surface. This is used to form the seal of the fitting instead of an O-Ring or tapered threads. Although JIC fittings share identical dimensions with AN (Army-Navy) fittings, they are not functionally interchangeable and should not be confused with one another.
A JIC fitting consists of three key components: the body, nut, and sleeve. The seal is achieved through metal-to-metal contact between the finished surface of the fitting nose and the inside of the flared tubing. The sleeve plays a crucial role by supporting the connection and evenly distributing compression during assembly. High-quality finishes help minimize the risk of leaks by reducing surface irregularities.
JIC fittings can withstand pressures of up to 7,700 psi and operate within a temperature range of -425°F to 1,200°F, depending on the material. While they are suitable for moderate vibration environments in most applications, enhanced versions are available for even greater resistance to pressure, temperature, and vibration.
JIC fittings offer many of the same benefits as other hydraulic connectors while also providing unique advantages that make them a preferred choice in the industry.
JIC fittings have long been the industry standard due to their simple yet efficient design, cost-effective manufacturing, and extensive size and style options. Their adaptability to both imperial and metric systems allows them to fit nearly any hose or port, making them widely accepted by both American and international companies.
Unlike O-rings, which are made of rubber or elastomeric materials and have limited temperature resistance, JIC fittings use a metal-to-metal seal that remains effective in both high- and low-temperature environments. This makes them a reliable choice for demanding applications.
JIC fittings provide exceptional versatility, allowing them to be seamlessly integrated into almost any hydraulic system. Their design enables easy disconnection and reconnection without compromising performance, further solidifying their status as an industry standard.
JIC fittings are widely used across various industries due to their reliability, durability, and adaptability. They are most commonly found in the military, aerospace, and plumbing sectors.
Historically, JIC fittings were specified under the military standard MIL-F-18866, though this has since been replaced by SAE J514. Despite the update, many industries still reference the older designation. Today, JIC fittings play a crucial role in military fuel delivery systems, particularly in connecting control valves with hydraulic tubing.
JIC fittings are extensively utilized in the aerospace sector, serving commercial airline manufacturers, NASA, and private space exploration companies. They are commonly found in commercial aircraft, airline ground support equipment, and aerospace fluid systems, where secure and leak-free connections are essential.
In the plumbing industry, JIC fittings are frequently used in flexible hydraulic systems to connect tubing efficiently. They can also function as adapters for female SAE swivels, enhancing system versatility and providing greater flexibility where needed.
