JIC fittings are one of the most widely used connection types in hydraulic systems, providing a reliable way to connect hoses, tubing, ports, and other hydraulic components. At Union Hydraulics, we carry a broad selection of JIC hydraulic fittings and adapters in multiple sizes, configurations, materials, and connection combinations for industrial, agricultural, mobile, and heavy equipment applications.
JIC fittings use a 37-degree flare to create a metal-to-metal seal between mating surfaces. Available configurations include male and female JIC fittings, straight adapters, 45° and 90° elbows, tees, bulkhead fittings, reducers, plugs, caps, and adapters that transition between JIC and other common hydraulic connection types.
What Are JIC Fittings?
JIC, or Joint Industry Council, fittings are hydraulic fittings that use a 37° flared sealing surface. They are commonly associated with SAE J514-style hydraulic connections and use straight threads to pull the mating flare surfaces together.
An important distinction is that the threads do not create the hydraulic seal on a JIC connection. The seal is formed where the male 37° flare contacts the corresponding female flare seat. Because the sealing surfaces do the work, thread sealant or PTFE tape is generally not used on the JIC portion of the connection.
JIC hydraulic fittings are commonly used on:
- Hydraulic hose assemblies
- Hydraulic tubing
- Pumps and hydraulic power units
- Cylinders and control valves
- Construction and heavy equipment
- Agricultural machinery
- Mobile hydraulic systems
- Industrial equipment and machinery
JIC fittings should also not be confused with SAE 45° flare fittings. Although the two connection styles may appear similar, the flare angles are different and they are not intended to be mated together.
Why JIC 37° Fittings Are Common in Hydraulic Systems
JIC fittings have become a standard connection choice across many hydraulic applications because they combine serviceability with a dependable metal-to-metal connection.
Metal-to-Metal 37° Flare Seal
The mating 37° flare surfaces form the hydraulic seal. When the correct fittings are properly assembled and the sealing surfaces are in good condition, the connection provides a dependable seal for hydraulic service.
Easy to Disconnect and Service
JIC fittings can be disconnected when equipment needs to be repaired, modified, or serviced. A fitting may also be reconnected when the threads, flare, and sealing surfaces remain in suitable condition.
Broad Range of Configurations
JIC connections are available in numerous sizes and configurations, making it possible to connect hoses and components while adapting between different port and fitting types.
Well Suited to Mobile and Industrial Hydraulics
The combination of a mechanical flare seal, straight-thread connection, and broad availability makes JIC fittings especially useful on equipment that requires dependable hydraulic connections and routine serviceability.
Common Types of JIC Hydraulic Fittings
Choosing the correct JIC fitting involves more than identifying the thread size. You also need to determine the connection type, fitting orientation, material, and the connection required on the opposite side of the adapter.
Common JIC fitting configurations include:
- Male JIC fittings (MJIC) – External straight threads with a male 37° flare
- Female JIC fittings (FJIC) – Internal threads with a female 37° flare seat
- Straight JIC adapters – Used for inline hydraulic connections
- 45° JIC elbows – Change hose or tubing direction while reducing the bend required in the line
- 90° JIC elbows – Used where a sharper directional change is needed
- JIC tees – Provide three connection points within a hydraulic circuit
- JIC bulkhead fittings – Allow a hydraulic connection to pass through a panel, bracket, or enclosure
- JIC reducers and expanders – Connect different fitting or tube sizes
- JIC plugs and caps – Close unused JIC connections
- JIC conversion adapters – Transition between JIC and other hydraulic connection types such as NPT, NPTF, ORB, and additional fitting styles
Union Hydraulics carries JIC fittings across a wide range of configurations, allowing you to narrow your search based on the exact connections required for your hydraulic system.
How to Identify the Correct JIC Fitting
One of the most common mistakes when replacing a hydraulic fitting is identifying it based only on the apparent thread diameter. Several hydraulic connection standards can look similar, so the complete connection should be identified before ordering a replacement.
When identifying a JIC fitting, check:
Male or Female Connection
Determine whether the connection uses external male threads or internal female threads and identify where the 37° flare sealing surface is located.
Thread Size
Measure and identify the thread diameter and thread pitch. JIC fittings commonly use UN/UNF straight threads, and the thread size should be matched to the appropriate JIC connection.
JIC Dash Size
Hydraulic fittings are frequently identified using dash sizes such as -04, -06, -08, -10, and -12. The dash size relates to the nominal tube outside diameter and is commonly used when identifying hydraulic hoses, tubing, and fittings.
Fitting Configuration
Determine whether you need a straight adapter, elbow, tee, bulkhead, reducer, cap, plug, or another configuration.
Opposite Connection
Many hydraulic adapters have a JIC connection on only one side. The other connection may be JIC, NPT, NPTF, ORB, or another hydraulic fitting standard.
Correctly identifying both ends of the fitting is essential before choosing a replacement.
JIC Thread and Dash Sizes
JIC fittings are available in a wide range of sizes. JIC dash sizes correspond to nominal tube outside diameter in sixteenths of an inch. For example, a -08 JIC connection corresponds to 8/16", or 1/2", tube OD. The dash size does not represent the actual thread diameter.
JIC Thread & Dash Size Chart
| JIC Dash Size | Tube OD | JIC Thread Size |
|---|---|---|
| -04 | 1/4" | 7/16"-20 |
| -05 | 5/16" | 1/2"-20 |
| -06 | 3/8" | 9/16"-18 |
| -08 | 1/2" | 3/4"-16 |
| -10 | 5/8" | 7/8"-14 |
| -12 | 3/4" | 1-1/16"-12 |
| -16 | 1" | 1-5/16"-12 |
| -20 | 1-1/4" | 1-5/8"-12 |
| -24 | 1-1/2" | 1-7/8"-12 |
| -32 | 2" | 2-1/2"-12 |
Important: JIC dash size corresponds to the nominal tube outside diameter in sixteenths of an inch; it is not the same as the thread diameter. When identifying an unknown fitting, verify the thread diameter and pitch, 37° flare seat, and male or female configuration before ordering.
JIC vs. NPT and ORB Connections
JIC, NPT, and ORB fittings are all commonly found in hydraulic systems, but they create seals differently.
JIC fittings seal at mating 37° flare surfaces.
NPT and NPTF fittings use tapered pipe threads, with the connection and sealing method differing from a JIC flare connection.
ORB fittings use straight threads along with an O-ring that seals against a machined port.
Adapters are available to transition between these connection styles, including JIC-to-NPT and JIC-to-ORB configurations. When selecting an adapter, both sides of the connection need to be correctly identified.
Choosing the Right JIC Fitting
Before ordering a JIC hydraulic fitting, consider:
- Male or female JIC connection
- Thread size and pitch
- JIC dash size
- Straight, 45°, 90°, tee, or other configuration
- Connection required on the opposite end
- Steel, stainless steel, brass, or other material
- Operating pressure
- Hydraulic fluid compatibility
- Temperature and operating environment
- Corrosion exposure
- Equipment and system requirements
Pressure ratings can vary based on fitting size, configuration, material, manufacturer, and application. Always verify that the specific fitting being used is appropriate for the operating conditions of the hydraulic system.
Where JIC Fittings Are Used
Because of their serviceability and broad range of available configurations, JIC hydraulic fittings are used throughout mobile and industrial hydraulic systems.
Common applications include:
- Excavators and construction equipment
- Tractors and agricultural machinery
- Hydraulic cylinders
- Hydraulic power units
- Pumps and motors
- Material-handling equipment
- Manufacturing machinery
- Truck and mobile hydraulic systems
- Maintenance and repair operations
Their widespread use also makes JIC fittings particularly useful when repairing or modifying existing hydraulic systems.
Shop JIC Fittings from Union Hydraulics
Union Hydraulics offers an extensive selection of JIC hydraulic fittings, 37° flare adapters, elbows, tees, bulkhead fittings, reducers, plugs, caps, and conversion adapters for hydraulic applications.
Use the available product options and filters to narrow your search by fitting type, size, configuration, material, connection, and manufacturer.
Need Help Identifying a JIC Fitting?
If you are replacing an existing hydraulic fitting and aren't certain of the connection, don't rely on appearance alone. Thread size, pitch, flare angle, fitting configuration, and the connection on both ends can all help determine the correct replacement.
Contact Union Hydraulics with the fitting information, measurements, specifications, or clear photos, and our team can help you identify the connection and find the appropriate JIC fitting for your application.