When you hit the market to purchase fittings for your hydraulic system, you have to choose between different types. You’ll find American thread types, British connections, French connections, German Din connections, and Japanese connections, among others.
In this post, our interest is in Japanese hydraulic fittings. Japanese hydraulic fittings differ from others in the market in some ways. They have their best applications, and some people mistake them for other similar hydraulic fittings.
Read on to find out more about Japanese hydraulic fittings, their types, and what makes them different.
What are Japanese Hydraulic Fittings?
As the name suggests, these hydraulic fittings originate from Japan. Japanese hydraulic fittings are made following the Japanese Industrial Standard. Hence, they are also known as JIS hydraulic fittings.
These hydraulic fittings typically feature JIS couplings with a 30-degree seat on the male end. The female end, on the other hand, has a 30-degree flared seat. Some variants come with 60-degree hose ends.
Japanese hydraulic fittings also usually feature British Standard pipe parallel threads, although some feature tapered threads. They are the go-to hydraulic fittings for OEM equipment manufactured not just in Japan but also in Korea and some other Asian countries.
Nevertheless, the fittings have their advantages. To start with, they are durable, as they are produced using high-quality steel materials. They don’t corrode easily and are perfect in hydraulic systems that require good heat insulation.
Furthermore, Japanese hydraulic fittings are easy to install in the smallest of spaces. Their adapters are relatively flexible, making them suitable for a range of applications.
However, note that these hydraulic fittings come in different sizes and designs. Therefore, you need to pay extra attention when purchasing to ensure you get a design that matches your hydraulic system.
Types of Japanese Hydraulic Fittings
There are five popular types of Japanese hydraulic fittings in the market. They include:
JIS B 0202
This type of Japanese hydraulic fitting uses 30-degree flare parallel pipe threads. It’s a male coupling, similar to the American 37° JIC flare, and its parallel threads resemble that of the BSPP fittings.
The fitting will only work with a JIS 30-degree flare female, as both have straight threads with a 30-degree seat. Although the threads are alike to BSPP fittings, you can’t interchange them as the British fittings have an inverted 30-degree seat.
However, there’s the JIS 30-degree inverted seat variant, with parallel pipe threads, which are interchangeable with BSPP fittings.
JIS Metric 60 Cone Seal
These fittings feature a 60-degree inverted flare seal at the female end and a 60-degree flare seat at the male end. They come with a metric thread and are typically made with stainless steel or zinc-plated carbon steel. As a result, they are long-lasting fittings.
JIS B 0203
The JIS B 0203 fittings come with Japanese standard tapered pipe threads. There is no difference between the BSPT and the JIS tapered pipe thread connection.
However, it won’t mate with BSPP females, as the JIS B 0203 lacks a 30-degree flare. On a JIS tapered pipe thread fitting, the seal is created directly on the threads.
Komatsu Style 30° Flare Parallel Threads
The only difference between the Komatsu style 30° Flare Parallel thread fittings and the Japanese style 30° Flare parallel fittings mentioned earlier are the threads. The Komatsu Style fittings feature Metric fine threads, similar to JIS B 0207 screw threads.
Komatsu Flange Fitting
This type of Japanese hydraulic fitting is similar to the SAE Code 61 flange fitting, and both are 100% interchangeable. However, the fittings come in different sizes with different O-ring dimensions. Therefore, you’ll need an SAE style O-ring to interchange the Komatsu Flange Fittings in any case.
What is the difference between JIS and JIC fittings?
The JIS and JIC fittings have similar names and feature similar flared tube connectors. However, they are different.
While JIS fittings follow the Japanese Industrial Standard, JIC fittings follow the Joint Industrial Council standard. The JIC is based in the UK, although the organization’s influence transcends the European continent.
JIC fittings feature a 37-degree flare tube connector. Meanwhile, JIS fittings feature 30-degree connectors with 60-degree cone fitting options. Therefore, you cannot interchange JIS for JIC.
Furthermore, JIS fittings are common with heavy equipment manufactured in Japan and Korea. Hence, they dominate the Eastern Asian market. On the other hand, JIC fittings are popular in the North American and European markets.
What is the difference between JIS and BSP fittings?
JIS and BSP fittings are another two popular fitting types that get mistaken, mainly because they feature the same 60-degree cone tube connectors.
The primary difference between the two is that BSP fittings follow the British Standard Pipe requirements. As mentioned here previously, JIS fittings follow the Japanese Industrial Standard.
Some JIS fittings are interchangeable with BSP fittings. For example, the JIS Tapered Pipe fitting is interchangeable with the BSPT connections, and BSPP connections are interchangeable with JIS parallel thread fittings.
However, BSP fittings are applicable as stud fittings with bonded seals via the undercut area. You can’t use JIS fittings for such applications.
Conclusion
In summary, Japanese hydraulic fittings follow the Japanese Industrial Standards (JIS) and are different from JIC and BSP hydraulic fittings. There are different types and they have been explained above. Contact us at Sinopulse Group today for your quality Japanese hydraulic fittings.