Image Description: JIC and NPTF Drawings
Looking for hydraulic components for hose assemblies and adapters can become a tedious task if you don’t have some level of basic understanding of them. Though hydraulic industries span across different regions of the world, they don’t conform to one unified standard.
It is essential to know these differences as the components manufactured under these standards may not be interchangeable. Selecting the wrong fitting for the job may result in thread wear, leaks, and improper connections. Here we look at the two most common types of fittings, NPT and JIC fittings, and identify their similarities and differences.
Standards
JIC fittings and adapters are based on the SAE J514 and MIL-DTL-18866 standards, whereas NPT fittings’ guidelines are outlined in the AMSE B1.20.1 standards. Both standards outline the characteristics, tolerances, and sizing variations for their respective components.
JIC fittings are often mistaken for other standards like SAE, AN, JIS, and Komatsu; however, subtle differences between them don’t make them interchangeable for use. We’ll get into these differences later on when we look at their characteristics and construction.
Threads
NPT, or National Pipe Tapered, gives you an indication of the kind of threads you can expect from these fittings. The threads are tapered, meaning they run at an angle of 1O 47’ (measured from the center axis of the NPT fitting). On the other hand, threads on JIC fittings run parallel to each other across the axis of the fitting.
NPT threads have flat crests and troughs, containing a 60O angle between each successive thread. JIC thread guidelines are identical to the ones outlined in the SAE – J512 standard. They can come in coarse, fine, or extra-fine thread sizes, each representing the thread count and diameters for the threads on their relevant male and female parts.
It may be possible to thread similarly sized male NPT fittings onto female JIC fittings; however, the reverse case is not possible. This practice should not be followed as the taper on male NPT fittings means that deeper threads will not interlock properly.
Flare
Both NPT and JIC fittings are machined with tapered ends. This increases the surface area of contact between the seats on interlocking parts and serves to form a tight seal between the two. However, their flare angle differs. JIC fittings come with a 37O flare angle, while the NPT fittings rely on just their tapered threads for sealing. As a result, JIC fittings offer better sealing capabilities and can withstand higher working pressures.
Other standards like Komatsu also offer flared fittings, but they also have different flare angles (30O). Also, as mentioned earlier, JIC thread sizing is identical to the SAE – J512 standard, but they differ in their flare angles and therefore are not interchangeable.
Which One Should You Use?
NPT fittings have been around for a while and come in many types, shapes, and sizes. However, the standard hasn’t evolved much since it was outlined. The ubiquity of parts may make it much more feasible for use in hydraulic systems, but its sealing properties are much to be desired when considering high-pressure applications. Hence, you may need to consider your working conditions before choosing NPT or JIC fittings.
FAQs
JIC fittings come with a 37O flare angle, while the NPT fittings rely on just their tapered threads for sealing. As a result, JIC fittings offer better sealing capabilities and can withstand higher working pressures.
What is the difference between JIC and an fittings? ›
As mentioned above, AN is produced to an extremely tight tolerance standard. JIC was standardized at a more attainable tolerance level to keep manufacturing costs and difficulty down. This means that a system that uses the AN standard may suffer if tolerances are too loose.
What is the difference between NPT and NPT fittings? ›
While NPT and NPTF thread forms are almost identical, NPT is a general-purpose thread that requires thread sealant for a leakproof seal, and you need to choose the sealant thoughtfully. NPTF creates a strong, leakproof mechanical seal without using a sealant.
Can you use NPT for hydraulic fittings? ›
NPT thread is the most common type of hydraulic fitting thread used in North America, from ¼ NPT through 2” being the most common. Other types of quick couplings are prominent in many types of industries and applications.
What is the difference between JIC and BSP fittings? ›
JIC: The 37-degree flare seating surface ensures a metal-to-metal seal, which is highly effective in high-pressure systems. BSP: The 30-degree cone seat, rounded threads, and the option for tapered threads provide a secure, leak-tight seal, especially when using bonded seals or O-rings.
What is the difference between JIC and NPT? ›
JIC fittings come with a 37O flare angle, while the NPT fittings rely on just their tapered threads for sealing. As a result, JIC fittings offer better sealing capabilities and can withstand higher working pressures.
Do JIC fittings need O rings? ›
Advantages of Using JIC Fittings:
The absence of an O-ring makes them desirable in high temperature applications. Can be disconnected and reconnected repeatedly without deformation (This is very useful in applications where equipment is frequently changed or swapped out.
Is NPT male or female? ›
NPT. NPT stands for National Pipe Thread and is an American standard thread. It may also be reffered to as MPT , MNPT or NPT (M) for male external threads and FPT, FNPT or NPT(F) for female interal threads. A thread sealant must always be used to achieve a leak free seal (except for NPTF).
What does a NPT fitting look like? ›
NPT fittings are easy to recognize, thanks to their distinctive tapered threads. The tapering allows for a deeper, more secure connection as the male and female fittings are twisted together. The farther the threads are engaged, the tighter the seal, resulting in a robust, leak-free connection.
What is the advantage of NPT? ›
Over the years, the NPT has helped prevent additional states from acquiring nuclear weapons, provided the confidence necessary to facilitate cooperation on the peaceful uses of nuclear energy, and fostered a security environment that has enabled dramatic reductions in nuclear stockpiles and that is essential for future ...
The best methods in how to properly seal hydraulic fittings are: On NPT, JIC and other all-metal fittings: Loctite 5452 thread sealant helps prevent rotation and leakage on these high-pressure fittings.
What is the flare angle of a JIC fitting? ›
The JIC male has straight threads and wa 37° flare seat. The JIC female has straight threads and a 37° flare seat. The Seal is made on the 37° flare seat.
What thread is the same as JIC? ›
JIC & UNO (O Ring Boss) thread forms are the same (ASME B1. 1). Method of sealing differs. JIC male has 37° flare which seals against 37° seat in female.
What is the most common JIC fitting? ›
The two most popular mated angle (flare) hydraulic fittings are JIC 37-degree and SAE 45-degree. JIC 37-degree flare fittings are often used for high pressure applications in off-road and agricultural equipment, such as hydraulic loaders, excavators and tractors.
When to use JIC fittings? ›
JIC (or SAE) 37-degree fittings and adapters are intended for industrial, construction and agricultural equipment, as well as other heavy machinery material handling applications. Hydraulic tube fittings made to J514/MIL-DTL-18866 include 37-degree flare seating face seal and 24-degree flareless type fittings.
Are an and JIC fittings compatible? ›
Don't Cross-Apply Fittings: While both fittings utilize the same thread size, the thread shapes of JIC and AN fittings are not the same.
How do I know if my hydraulic fittings are JIC? ›
The tip taper angle of 37° is the main defining feature for identifying JIC fittings. The 37° taper angle is visually distinct for leading to a sharper tip, compared to the close cousin SAE which has a 45° angle.
What are the three types of fittings? ›
Cap, Plug and Nipple Fittings
The difference is that a plug fits into the threaded pipe opening to make the seal, while caps fit over the opening.
What are Type A fittings known as? ›
Type A compression fittings, also known as non-manipulative fittings, are what most people know as Compression Fittings. Compared to Type B fittings, they do not require any modification to the pipe or tubing.
