REFERENCE · JIS B2220

JIS B2220 pressure–temperature ratings

JIS B2220 · JIS B2220:2012 · verified 2026-11-04

Pressure-temperature ratings Material groups Tolerances Marking Types and facings

Reference tables are transcribed from JIS B2220:2012; table numbers, printed page numbers and cell values keep the standard's original wording.

Table 11 of JIS B2220:2012 is the rating table that turns a nominal JIS K number into a maximum working pressure at a stated fluid temperature. It covers nominal pressures 5K, 10K, 16K, 20K, 30K, 40K and 63K, the JIS material groups of Table 5 and their ASTM reference groups from Table 6, and three divisions, I, II and III.

Read each row as nominal pressure, specified material group, reference material group and division. The division is not chosen by the buyer: Table 12 assigns Division I, II or III according to flange classification, nominal size and material group, and Division III is the most restrictive. Values are in MPa. The first temperature column runs from T_L — a minimum working temperature equal to or below the normal temperature — to 120 °C; heat-resistant groups carry values up to 510 °C. A dash means the standard gives no rating for that cell.

JIS K ratings are nominal labels, not working pressures. For group 1.1, Division I, a 5K flange is rated 0.7 MPa, a 10K flange 1.4 MPa, a 16K flange 2.7 MPa, a 20K flange 3.4 MPa and a 30K flange 5.1 MPa at up to 120 °C; the same flanges fall to 0.5, 1.0, 2.3, 2.9 and 4.3 MPa at 300 °C. Always use the row that matches the actual material and the division that Table 12 assigns to the flange.

StandardJIS B2220:2012

TableTable 11, clause 9

UnitMPa

Nominal pressures5K–63K

Material groups001–023b / 1.1–2.3

DivisionsI, II, III

TemperatureT_L to 510 °C

Table 11 — max working pressure by material group and division

The table keeps the printed order: nominal pressure, specified material group, reference material group, division, then the maximum working pressure at each fluid temperature. Footnotes a) to e) remove named grades from a group, and NOTES 1 to 5 state how the table is applied.

The 450, 475, 490, 500 and 510 °C columns occur only in the 30K, 40K and 63K rows; for 5K to 20K they are printed as dashes.

Table 11 (pp. 15–16) — pressure-temperature rating, maximum working pressure in MPa

Nominal pressure	Specified material group No.	Reference material group No.	Division	T_L to 120°C	220°C	300°C	350°C	400°C	425°C	450°C	475°C	490°C	500°C	510°C
5K	001, 002, 003a	1.1	I	0.7	0.6	0.5	—	—	—	—	—	—	—	—
5K	001, 002, 003a	1.1	II	0.5	0.5	0.5	—	—	—	—	—	—	—	—
5K	001, 002, 003a	1.1	III	0.5	—	—	—	—	—	—	—	—	—	—
5K	021a, 021b, 022a, 022b	2.1, 2.2	I	0.7	0.6	0.5	—	—	—	—	—	—	—	—
5K	021a, 021b, 022a, 022b	2.1, 2.2	II	0.5	0.5	0.5	—	—	—	—	—	—	—	—
5K	021a, 021b, 022a, 022b	2.1, 2.2	III	0.5	—	—	—	—	—	—	—	—	—	—
5K	023a, 023b	2.3	I	0.7	0.6	0.5	—	—	—	—	—	—	—	—
5K	023a, 023b	2.3	II	0.5	0.5	0.5	—	—	—	—	—	—	—	—
5K	023a, 023b	2.3	III	0.5	—	—	—	—	—	—	—	—	—	—
10K	001, 002, 003a	1.1	I	1.4	1.2	1.0	—	—	—	—	—	—	—	—
10K	001, 002, 003a	1.1	II	1.0	1.0	1.0	—	—	—	—	—	—	—	—
10K	001, 002, 003a	1.1	III	1.0	—	—	—	—	—	—	—	—	—	—
10K	021a, 021b, 022a, 022b	2.1, 2.2	I	1.4	1.2	1.0	—	—	—	—	—	—	—	—
10K	021a, 021b, 022a, 022b	2.1, 2.2	II	1.0	1.0	0.9	—	—	—	—	—	—	—	—
10K	021a, 021b, 022a, 022b	2.1, 2.2	III	1.0	—	—	—	—	—	—	—	—	—	—
10K	023a, 023b	2.3	I	1.4	1.2	1.0	—	—	—	—	—	—	—	—
10K	023a, 023b	2.3	II	1.0	0.9	0.8	—	—	—	—	—	—	—	—
10K	023a, 023b	2.3	III	1.0	—	—	—	—	—	—	—	—	—	—
16K	002, 003a	1.1	I	2.7	2.5	2.3	2.1	1.8 a)	1.6 a)	—	—	—	—	—
16K	002, 003a	1.1	II	1.6	1.6	1.6	—	—	—	—	—	—	—	—
16K	002, 003a	1.1	III	1.6	—	—	—	—	—	—	—	—	—	—
16K	021a, 021b, 022a, 022b	2.1, 2.2	I	2.7	2.5	2.3	2.1	1.8	1.6	—	—	—	—	—
16K	021a, 021b, 022a, 022b	2.1, 2.2	II	1.6	1.6	1.6	1.6	1.5	1.5	—	—	—	—	—
16K	021a, 021b, 022a, 022b	2.1, 2.2	III	1.6	—	—	—	—	—	—	—	—	—	—
16K	023a, 023b	2.3	I	2.7	2.5	2.3	2.1	1.8	1.6	—	—	—	—	—
16K	023a, 023b	2.3	II	1.6	1.6	1.5	1.4	1.3	1.3	—	—	—	—	—
16K	023a, 023b	2.3	III	1.6	—	—	—	—	—	—	—	—	—	—
20K	002, 003a	1.1	I	3.4	3.1	2.9	2.6	2.3 a)	2.0 a)	—	—	—	—	—
20K	002, 003a	1.1	II	2.0	2.0	2.0	—	—	—	—	—	—	—	—
20K	002, 003a	1.1	III	2.0	—	—	—	—	—	—	—	—	—	—
20K	021a, 021b, 022a, 022b	2.1, 2.2	I	3.4	3.1	2.9	2.6	2.3	2.0	—	—	—	—	—
20K	021a, 021b, 022a, 022b	2.1, 2.2	II	2.0	2.0	2.0	2.0	1.9	1.9	—	—	—	—	—
20K	021a, 021b, 022a, 022b	2.1, 2.2	III	2.0	—	—	—	—	—	—	—	—	—	—
20K	023a, 023b	2.3	I	3.4	3.1	2.9	2.6	2.3	2.0	—	—	—	—	—
20K	023a, 023b	2.3	II	2.0	2.0	1.9	1.7	1.7	1.7	—	—	—	—	—
20K	023a, 023b	2.3	III	2.0	—	—	—	—	—	—	—	—	—	—
30K	002, 003a	1.1	I	5.1	4.6	4.3	3.9	3.4 a)	3.0 a)	—	—	—	—	—
30K	013a	1.5	I	5.1	4.6	4.3	3.9	3.8 b)	3.6 b)	3.4 b)	3.0 b)	—	—	—
30K	015a	1.9	I	5.1	4.6	4.3	3.9	3.8	3.6	3.4	3.2	3.0	—	—
30K	021a, 021b, 022a, 022b	2.1, 2.2	I	5.1	4.6	4.3	3.9	3.8	3.6	3.4 c)	3.2 c) d)	3.0 c) d)	—	—
30K	021a, 021b, 022a, 022b	2.1, 2.2	II	3.9	3.6	3.4	3.0	2.5	2.3	2.3 c)	2.3 c) d)	2.3 c) d)	—	—
30K	023a, 023b	2.3	I	5.1	4.6	4.3	3.9	3.8	3.6	3.4 e)	—	—	—	—
30K	023a, 023b	2.3	II	3.5	3.0	2.9	2.6	2.1	2.0	2.0 e)	—	—	—	—
40K	002, 003a	1.1	I	6.8	6.2	5.7	5.2	4.6 a)	4.0 a)	—	—	—	—	—
40K	013a	1.5	I	6.8	6.2	5.7	5.2	5.1 b)	4.8 b)	4.5 b)	4.0 b)	—	—	—
40K	015a	1.9	I	6.8	6.2	5.7	5.2	5.1	4.8	4.5	4.2	4.0	3.8	3.6
40K	015a	1.9	II	6.8	6.2	5.7	5.2	5.1	4.8	4.5	4.2	4.0	3.1	2.7
40K	021a, 021b, 022a, 022b	2.1, 2.2	I	6.8	6.2	5.7	5.2	5.1	4.8	4.5 c)	4.2 c) d)	4.0 c) d)	3.8 c) d)	3.6 c) d)
40K	021a, 021b, 022a, 022b	2.1, 2.2	II	5.2	4.8	4.5	4.1	3.4	3.1	3.1 c)	3.1 c) d)	3.1 c) d)	3.0 c) d)	3.0 c) d)
40K	023a, 023b	2.3	I	6.8	6.2	5.7	5.2	5.1	4.8	4.5 e)	—	—	—	—
40K	023a, 023b	2.3	II	4.9	4.0	3.9	3.5	2.9	2.7	2.7 e)	—	—	—	—
63K	002, 003a	1.1	I	10.7	9.7	9.0	8.1	7.2 a)	6.3 a)	—	—	—	—	—
63K	013a	1.5	I	10.7	9.7	9.0	8.1	8.0 b)	7.6 b)	7.1 b)	6.3 b)	—	—	—
63K	015a	1.9	I	10.7	9.7	9.0	8.1	8.0	7.6	7.1	6.6	6.3	5.9	5.6
63K	015a	1.9	II	10.7	9.7	9.0	8.1	8.0	7.6	7.1	6.6	6.3	4.6	4.0
63K	021a, 021b, 022a, 022b	2.1, 2.2	I	10.7	9.7	9.0	8.1	8.0	7.6	7.1 c)	6.6 c) d)	6.3 c) d)	5.9 c) d)	5.6 c) d)
63K	021a, 021b, 022a, 022b	2.1, 2.2	II	8.1	7.1	6.7	6.2	5.1	4.7	4.6 c)	4.6 c) d)	4.6 c) d)	4.5 c) d)	4.5 c) d)
63K	023a, 023b	2.3	I	10.7	9.7	9.0	8.1	7.2	6.6	6.4 e)	—	—	—	—
63K	023a, 023b	2.3	II	7.4	6.0	5.8	5.2	4.3	4.0	4.0 e)	—	—	—	—

Maximum working pressure in MPa. Fluid temperatures are in °C. T_L is a minimum working temperature equal to or below the normal temperature. Interpolate proportionally between tabulated temperatures; do not extrapolate. A dash (—) means the standard gives no rating for that combination. Columns 450 to 510 °C apply to the 30K, 40K and 63K rows only.

NOTE 1Light flanges (L) at nominal pressure 10K have their own limit in clause 9: steady flow at 120 °C or less and 0.7 MPa or less. Table 7 lists the nominal sizes available in the light type.
NOTE 2The specified material column refers to the group numbers of Table 5; the reference material column refers to the ASTM-based groups of Table 6.
NOTE 3Division II restricts a flange more than Division I, and Division III more than Division II. Table 12 states which division applies, based on the flange classification and nominal size.
NOTE 4T_L is the lowest working temperature considered, at or below the normal temperature. Using a flange below that temperature requires agreement between the buyer and the manufacturer.
NOTE 5Pressures between two tabulated temperatures are found by proportional interpolation.
a)This rating does not cover SC 480 of JIS G 5101 (group 002) or CL1 of ASTM A 537 (group 1.1).
b)This rating does not cover LC1 of ASTM A 352 (group 1.5).
c)This rating does not cover CF3 of ASTM A 351 (groups 021b and 2.1).
d)This rating does not cover CF3M of ASTM A 351 (groups 022b and 2.2).
e)This rating does not cover 304L of ASTM A 240 (groups 023a and 2.3) or F304L of ASTM A 182.

How to apply the ratings

A JIS K number is a nominal label, not a working pressure. The allowable pressure depends on the material group, the division and the fluid temperature at the same time.

Find the division first. Table 12 assigns Division I, II or III to each flange classification (SOP, SOH, SW, LJ, TR, WN, IT, BL) and nominal size for every material group; Division III is the most restricted and Division II sits between I and III.
Then find the material. A flange made from a JIS material is rated by the specified group number (001 to 023b, Table 5); a flange made from the ASTM reference material is rated by the reference group number (1.1 to 2.3, Table 6).
Read across to the design temperature. Between two tabulated temperatures the pressure is obtained by proportional interpolation; outside the tabulated range, or where a dash is printed, the standard gives no rating and extrapolation is not permitted.
Check the footnotes. Footnotes a) to e) exclude specific grades — for example, at 16K and 20K the 400 °C and 425 °C values for group 1.1 do not apply to SC 480 or to ASTM A 537 CL1.
Group 001 appears in the 5K and 10K rows only; from 16K upward the carbon-steel rows start at group 002/003a, and the 30K, 40K and 63K rows add the low-alloy groups 013a and 015a.
Zinc-coated (white) flanges are restricted to 300 °C maximum working temperature, and light 10K flanges to steady flow at 120 °C or less and 0.7 MPa or less (clause 9).

FAQ

What does 10K mean on a JIS flange?: K is the nominal pressure in kgf/cm², so 10K is nominally 10 kgf/cm² (about 1.0 MPa). It is not the maximum working pressure: Table 11 gives 1.4 MPa at up to 120 °C for a 10K flange in material group 1.1, Division I, falling to 1.0 MPa at 300 °C. The allowable pressure depends on the material and the division.
Is JIS 10K the same as ASME Class 150?: No. Both are loosely described as about 1 MPa or 150 lb nominal, but the outside diameters, bolt circles and bolt sizes differ, so a JIS 10K flange does not bolt to an ASME Class 150 flange. The ratings also differ: ASME B16.5 Class 150 in ASTM A105 allows 19.6 bar at 38 °C, against 1.4 MPa (14 bar) for JIS 10K group 1.1 Division I up to 120 °C.
Why does the same 20K flange have three different ratings?: Because Table 11 gives one rating per division, and Table 12 assigns Division I, II or III according to flange classification, nominal size and material group. For 20K group 002/003a the 120 °C value is 3.4 MPa in Division I but 2.0 MPa in Divisions II and III; Division III is the most restricted.
Can I interpolate or extrapolate a JIS B2220 rating?: Interpolate proportionally between the listed temperatures, but do not extrapolate: where a dash is printed the standard gives no rating. Ratings above 425 °C are published only for the 30K, 40K and 63K rows and only for the material groups whose cells carry values, up to 510 °C.

Sources

JIS B2220:2012, clause 9 and Table 11 (PDF pp. 20–21; printed pp. 15–16)
JIS B2220:2012, clause 10 and Table 12 (PDF p. 22; printed p. 17)
JIS B2220:2012, clause 8, Tables 5 and 6 (PDF pp. 10–11; printed pp. 5–6)
JIS B2220:2012, clause 9, light-flange and white-flange limits (PDF p. 12; printed p. 7)

JIS B2220:2012 (PDF supplied for this project)