JIS 4-Bolt Flanges are frequently used in fluid power systems. There are two pressure ratings: Type I Code 61 and Type II Code 62.
As with DIN flanges, the unthreaded female port in a JIS flange has 4 bolt holes at the corners. The male flanged head has holes to match the 
port and a grooved recess for an O-ring.
The O-ring makes the seal between the flanged head and the flat surface on the port. Threaded bolts are inserted through the 4 bolt holes to securely connect the flange to another mating flange or the flat surface of the port.
Two pressure ratings for JIS 4-Bolt Flanges
Type 1 is similar in application to SAE Code 61. However, like SAE Code 62, Type 2 JIS 4-Bolt Flange is the heavy-duty series. JIS flange bolt head diameters and bolt diameters are larger in the Type 2, and like DIN flanges, inch or metric bolts can be used. This JIS B 8363 flange is also interchangeable with both DIN 20066 and SAE J518.
This blog is an excerpt from our latest whitepaper, Distinguishing the Different Types of International Flanges.
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