What is a JIC fitting? This question often arises when dealing with hydraulic and fluid systems. A JIC fitting, or Joint Industry Council fitting, is a widely used standard for hydraulic connectors.
It ensures reliable connections in high-pressure environments. In this article, I’ll share my expertise to help you understand what a JIC fitting is, its advantages, and how to use it effectively. If you have any questions about the content, feel free to contact us.
What Are JIC Fittings?

Definition and Origin of JIC Fittings
Clearly define JIC fittings: A JIC fitting, which stands for Joint Industry Council fitting, is a standardized connector widely used in hydraulic systems. Its design is aimed at achieving reliable connections and seals.
Elaborate on the origin background of JIC fittings: In the mid – 20th century, with the rapid development of industry, hydraulic technology was increasingly applied in various fields. However, the market was plagued by chaotic fitting specifications and standards.
Fittings produced by different manufacturers lacked universality in dimensions and performance, causing great inconvenience to equipment maintenance, upgrades, and system integration. To address this issue, relevant industry associations and enterprises jointly established a specialized organization.
Through extensive research and practice, they formulated the JIC fitting standards to meet the industry’s urgent need for unified and high – performance fittings.
Common Specification Sizes
Size Label | Cone Width “a” (inches) | Thread Width “b” (inches) | Thread Specification “c” | Shoulder Width “d” (inches) | Shoulder Diameter “e” (inches) | Fitting Length “f” (inches) | Bore Diameter “h” (inches) | Tip Diameter “i” (inches) |
---|---|---|---|---|---|---|---|---|
2 | 0.111 | 0.208 | 5/16”-24 unf | 0.067 | 0.250 | 0.448 | 0.062 | 0.083 |
3 | 0.11 | 0.239 | 3/8”-24 unf | 0.067 | 0.312 | 0.479 | 0.125 | 0.146 |
4 | 0.114 | 0.282 | 7/16”-20 unf | 0.080 | 0.364 | 0.550 | 0.172 | 0.193 |
5 | 0.114 | 0.282 | 1/2”-20 unf | 0.080 | 0.426 | 0.550 | 0.234 | 0.255 |
6 | 0.108 | 0.275 | 9/16”-18 unf | 0.090 | 0.481 | 0.556 | 0.281 | 0.318 |
8 | 0.155 | 0.310 | 3/4”-16 unf | 0.098 | 0.659 | 0.657 | 0.406 | 0.426 |
10 | 0.155 | 0.385 | 7/8”-14 unf | 0.111 | 0.772 | 0.758 | 0.531 | 0.539 |
12 | 0.185 | 0.424 | 1 – 1/16”-12 un | 0.130 | 0.943 | 0.943 | 0.609 | 0.664 |
14 | 0.186 | 0.450 | 1 – 3/16”-12 un | 0.129 | 1.068 | 0.890 | 0.719 | 0.788 |
16 | 0.186 | 0.471 | 1 – 5/16”-12 un | 0.129 | 1.193 | 0.911 | 0.844 | 0.913 |
Structural Analysis of JIC Fittings
- Protective Coatings
Many JIC fittings come with protective coatings, such as zinc plating or anodizing, to enhance their resistance to wear and corrosion. This layer safeguards the fittings from environmental damage and extends their operational lifespan. - Flared Ends
The hallmark of JIC fittings is the 37-degree flared end, which creates a precise seal. This flare acts as the primary sealing surface, distributing pressure evenly across the connection and preventing localized stress or leaks. - Threaded Sections
The threads on JIC fittings are designed for strength and precision. They are unified threads, which allow smooth and repeatable assembly. The threading provides sufficient clamping force to hold the fitting securely, even under vibrations or dynamic loads. - Material Thickness and Durability
JIC fittings are manufactured with consistent wall thickness, ensuring uniform strength across the fitting. This structural integrity allows the fittings to withstand extreme pressures and temperatures without deforming. - Standardized Dimensions
JIC fittings adhere to the SAE J514 standard, which defines their dimensions, thread pitch, and flare angle. This standardization allows them to be interchangeable across systems, enhancing their usability in global industrial applications. - Versatile Design for Fluid Flow
The internal diameter of JIC fittings is optimized to minimize turbulence and pressure drops during fluid flow. This ensures efficient performance, whether the fitting is used for hydraulic fluids, gases, or other mediums.
How Do JIC Fittings Work?
- Corrosion-Resistant Materials
Typically made from stainless steel, brass, or carbon steel, JIC fittings are resistant to corrosion, making them suitable for harsh environments. This material choice prolongs the life of the fittings, even when exposed to moisture, chemicals, or extreme temperatures. - Sealing Mechanism with a 37-Degree Flare
JIC fittings achieve a leak-proof seal through a 37-degree flare on the male and female mating surfaces. When the two surfaces are brought together and tightened, the flared edges compress to create a strong, reliable seal. This design eliminates the need for additional sealants, such as Teflon tape, and ensures reusability without compromising the connection’s integrity. - Threaded Coupling for Secure Attachment
The threads on JIC fittings serve to hold the male and female parts tightly together. These threads are manufactured to precise SAE J514 standards, ensuring uniformity and compatibility across different systems. The threading also allows for a controlled level of torque to avoid over-tightening or damage. - High-Pressure Compatibility
JIC fittings are engineered to handle high-pressure applications, often up to 10,000 PSI, depending on the material and size. The robust connection ensures that fluid flow remains uninterrupted, making them ideal for hydraulic and industrial systems. - Self-Aligning Design
The flared design helps align the male and female ends during installation, reducing the risk of cross-threading. Proper alignment ensures that the sealing surfaces meet perfectly, which is critical for preventing leaks and maintaining performance under pressure.
What Does JIC Stand for in Fittings?

JIC stands for Joint Industry Council, which developed the standard for these fittings. They are identified by their 37-degree flare seating surface, providing a leak-proof seal without requiring additional sealing compounds or tapes.
Key Features of JIC Fittings
- Material Durability: Often made from stainless steel or brass, they withstand extreme conditions.
- Versatility: Compatible with various hydraulic systems.
- High-Pressure Capability: Ideal for demanding applications in industries such as aerospace, automotive, and construction.
Applications of JIC Fittings
JIC fittings are versatile and used across numerous sectors. Here are some common applications:
- Hydraulic Systems: Essential for connecting components in hydraulic machinery, ensuring leak-proof and high-pressure performance.
- Fuel Lines: Commonly used in automotive fuel delivery systems for reliability and durability.
- Aerospace Industry: Withstanding extreme conditions, these fittings are critical for aircraft hydraulic and fuel systems.
- Marine Applications: Corrosion-resistant versions of JIC fittings are used in ships and offshore platforms.
- Industrial Machinery: Providing robust connections for high-pressure hydraulic and pneumatic systems.
How to Install and Maintain a JIC Fitting
Proper installation and maintenance are critical for ensuring the performance and longevity of JIC fittings. Follow these steps:

Step 1: Gather Your Tools
Before starting, ensure you have:
- The correct JIC fitting size and type.
- A clean workspace and tools, including adjustable wrenches and a torque wrench.
Step 2: Inspect the Components
Examine both the male and female ends for damage, dirt, or defects. A clean and undamaged surface ensures a proper seal and prevents leaks.
Step 3: Align the Fitting Ends
Hold the male and female fittings together, ensuring the 37-degree flared surfaces are perfectly aligned.
Step 4: Hand-Tighten
Thread the fittings together by hand to avoid cross-threading, which can damage the threads.
Step 5: Tighten Using a Wrench
Using a wrench, tighten the connection according to the manufacturer’s recommended torque. Over-tightening can damage the fitting.
Step 6: Test for Leaks
Run the hydraulic or fluid system to ensure there are no leaks. Re-tighten the fitting if necessary.
Step 7: Regular Maintenance
Periodically inspect and clean the fittings to ensure long-term performance. Replace any damaged components immediately.
Conclusion
In summary, JIC fittings are essential components in hydraulic and fluid systems, offering durability, reliability, and versatility. By understanding their specifications, applications, and proper installation steps, you can ensure optimal performance in your systems.
If you have questions about the article or need more information, feel free to contact us. If you’re interested in our products, visit our homepage or request our product catalog.
FAQs About Jic Fitting
What Does JIC Mean in Fittings?
JIC stands for Joint Industry Council. These fittings use a 37-degree flare design to create a secure and leak-free connection.
What is the Difference Between NPT and JIC Fittings?
NPT (National Pipe Thread) fittings rely on thread deformation for sealing, while JIC fittings use a 37-degree flare, ensuring a reusable and leak-proof connection.
What is the Difference Between SAE and JIC Fittings?
SAE fittings have different thread standards and sealing mechanisms compared to JIC. JIC fittings focus on a flared connection, while SAE can include o-ring seals.
What is the JIC Fitting Equivalent To?
JIC fittings are equivalent to AN (Army-Navy) fittings in terms of design and dimensions, but JIC is used in industrial applications, while AN is for military and aerospace.
What Size is #6 JIC Fitting?
A #6 JIC fitting corresponds to a 3/8-inch tube outer diameter and 9/16-18 thread size.
Where to Buy Fittings?
For customized and high-quality fittings, contact Dingfeng. We offer a full range of fittings and are ready to assist you.