JIS Flanges

Japanese Industrial Standards Pipe Flange Specifications

What Are JIS Flanges?

JIS (Japanese Industrial Standards) flanges are manufactured per JIS B2220, the Japanese standard for steel pipe flanges. JIS flanges use metric dimensions and K-class pressure ratings. They are commonly used in Japan, Southeast Asia, and projects involving Japanese engineering firms or equipment suppliers.

Pressure Ratings (K-Class)

JIS flanges use K-class ratings: 2K, 5K, 10K, 16K, 20K, 30K, 40K, and 63K. The K number represents the approximate maximum working pressure in kgf/cm² at ambient temperature. JIS 10K is roughly equivalent to ASME Class 150. JIS 20K is roughly equivalent to ASME Class 300. JIS 40K is roughly equivalent to ASME Class 600.

JIS B2220 Flange Types

  • Slip-On (SOH) — Hubbed
  • Slip-On (SOP) — Plate
  • Weld Neck (WN)
  • Blind (BL)
  • Socket Weld (SW)
  • Threaded (TR)
  • Lap Joint (LJ)

JIS uses different type designations than ASME.

Access flange data offline in the field.

Download the Flange Bolt Chart app for instant access to flange specifications, bolt sizes, and torque values — no internet required.

App Store badge for the Flange Bolt Chart appGet it on Google Play

JIS vs ASME Flanges

Key differences: JIS uses metric dimensions (mm), ASME uses imperial (inches). JIS uses K-class pressure ratings, ASME uses Class ratings. Bolt patterns and flange ODs differ significantly. JIS flanges are generally NOT interchangeable with ASME flanges. Some JIS 10K flanges can mate with ASME Class 150 in specific sizes, but this should be verified on a case-by-case basis.

Common Materials

  • JIS G3214 SUS F304 — Equivalent to A182 F304
  • JIS G3214 SUS F316 — Equivalent to A182 F316
  • JIS G3202 SFVC2A — Equivalent to A105
  • SS400 — General structural steel

Related References