JIS B 2401 Metric O-Rings
JIS B 2401 Metric O-Rings for Japanese Standard Sealing Applications
Reliable Metric O-Ring Solutions Based on Japanese Industrial Standards
When designing or maintaining industrial equipment, selecting the correct O-ring size standard is critical for achieving reliable sealing performance. While AS568 and ISO metric sizes are widely used worldwide, many Japanese-designed machines and hydraulic systems rely on JIS B 2401 Metric O-Rings.
JIS B 2401 provides standardized O-ring dimensions developed for industrial sealing applications in Japan. These metric O-rings are commonly used in hydraulic equipment, automotive systems, industrial machinery, and imported Japanese equipment where precise dimensional compatibility is required.
Using the correct JIS standard size helps prevent common sealing problems caused by incorrect cross-section, excessive compression, or insufficient groove filling.
Click on a Series below to view the size chart for that particular series, or scroll down to see the size chart for all JIS sizes sorted from smallest to largest, C/S then I.D.
All JIS Sizes – Sorted by Size
| Reference | C/S (MM) | L.D.(MM) | C/S (Inch) | I.D. (Inch) |
|---|---|---|---|---|
| S3 | 1.5 | 2.5 | 0.059 | 0.098 |
| S4 | 1.5 | 3.5 | 0.059 | 0.138 |
| S5 | 1.5 | 4.5 | 0.059 | 0.177 |
| S6 | 1.5 | 5.5 | 0.059 | 0.217 |
| S7 | 1.5 | 6.5 | 0.059 | 0.256 |
| S8 | 1.5 | 7.5 | 0.059 | 0.295 |
| S9 | 1.5 | 8.5 | 0.059 | 0.335 |
| S10 | 1.5 | 9.5 | 0.059 | 0.374 |
| S11.2 | 1.5 | 10.7 | 0.059 | 0.421 |
| S12 | 1.5 | 11.5 | 0.059 | 0.453 |
| S12.5 | 1.5 | 12 | 0.059 | 0.472 |
| S14 | 1.5 | 13.5 | 0.059 | 0.531 |
| S15 | 1.5 | 14.5 | 0.059 | 0.571 |
| S16 | 1.5 | 15.5 | 0.059 | 0.61 |
| S7 | 1.5 | 6.5 | 0.059 | 0.256 |
| S8 | 1.5 | 7.5 | 0.059 | 0.295 |
| S9 | 1.5 | 8.5 | 0.059 | 0.335 |
| S10 | 1.5 | 9.5 | 0.059 | 0.374 |
| S11.2 | 1.5 | 10.7 | 0.059 | 0.421 |
| S12 | 1.5 | 11.5 | 0.059 | 0.453 |
| S12.5 | 1.5 | 12 | 0.059 | 0.472 |
| S14 | 1.5 | 13.5 | 0.059 | 0.531 |
| S15 | 1.5 | 14.5 | 0.059 | 0.571 |
| S16 | 1.5 | 15.5 | 0.059 | 0.61 |
| S18 | 1.5 | 17.5 | 0.059 | 0.689 |
| S20 | 1.5 | 19.5 | 0.059 | 0.768 |
| S22 | 1.5 | 21.5 | 0.059 | 0.846 |
| P3 | 1.9 | 2.8 | 0.075 | 0.11 |
| P4 | 1.9 | 3.8 | 0.075 | 0.15 |
| P5 | 1.9 | 4.8 | 0.075 | 0.189 |
| P6 | 1.9 | 5.8 | 0.075 | 0.228 |
| P7 | 1.9 | 6.8 | 0.075 | 0.268 |
| P8 | 1.9 | 7.8 | 0.075 | 0.307 |
| P9 | 1.9 | 8.8 | 0.075 | 0.346 |
| P10 | 1.9 | 9.8 | 0.075 | 0.386 |
| S22.4 | 2 | 21.9 | 0.079 | 0.862 |
| S24 | 2 | 23.5 | 0.079 | 0.925 |
| S25 | 2 | 24.5 | 0.079 | 0.965 |
| S26 | 2 | 25.5 | 0.079 | 1.004 |
| S28 | 2 | 27.5 | 0.079 | 1.083 |
| S29 | 2 | 28.5 | 0.079 | 1.122 |
| S30 | 2 | 29.5 | 0.079 | 1.161 |
| S31.5 | 2 | 31 | 0.079 | 1.22 |
| S32 | 2 | 31.5 | 0.079 | 1.24 |
| S34 | 2 | 33.5 | 0.079 | 1.319 |
| S35 | 2 | 34.5 | 0.079 | 1.358 |
| S35.5 | 2 | 35 | 0.079 | 1.378 |
| S36 | 2 | 35.5 | 0.079 | 1.398 |
| S38 | 2 | 37.5 | 0.079 | 1.476 |
| S39 | 2 | 38.5 | 0.079 | 1.516 |
| S40 | 2 | 39.5 | 0.079 | 1.555 |
| S42 | 2 | 41.5 | 0.079 | 1.634 |
| S44 | 2 | 43.5 | 0.079 | 1.713 |
| S45 | 2 | 44.5 | 0.079 | 1.752 |
| S46 | 2 | 45.5 | 0.079 | 1.791 |
| S48 | 2 | 47.5 | 0.079 | 1.87 |
| S50 | 2 | 49.5 | 0.079 | 1.949 |
| S53 | 2 | 52.5 | 0.079 | 2.067 |
| S55 | 2 | 54.5 | 0.079 | 2.146 |
| S56 | 2 | 55.5 | 0.079 | 2.185 |
| S60 | 2 | 59.5 | 0.079 | 2.343 |
| S63 | 2 | 62.5 | 0.079 | 2.461 |
| S65 | 2 | 64.5 | 0.079 | 2.539 |
| S67 | 2 | 66.5 | 0.079 | 2.618 |
| S70 | 2 | 69.5 | 0.079 | 2.736 |
| S71 | 2 | 70.5 | 0.079 | 2.776 |
| S75 | 2 | 74.5 | 0.079 | 2.933 |
| S80 | 2 | 79.5 | 0.079 | 3.13 |
| S85 | 2 | 84.5 | 0.079 | 3.327 |
| S90 | 2 | 89.5 | 0.079 | 3.524 |
| S95 | 2 | 94.5 | 0.079 | 3.72 |
| S100 | 2 | 99.5 | 0.079 | 3.917 |
| S105 | 2 | 104.5 | 0.079 | 4.114 |
| S110 | 2 | 109.5 | 0.079 | 4.311 |
| S112 | 2 | 111.5 | 0.079 | 4.39 |
| S115 | 2 | 114.5 | 0.079 | 4.508 |
| S120 | 2 | 119.5 | 0.079 | 4.705 |
| S125 | 2 | 124.5 | 0.079 | 4.902 |
| S130 | 2 | 129.5 | 0.079 | 5.098 |
| S132 | 2 | 131.5 | 0.079 | 5.177 |
| S135 | 2 | 134.5 | 0.079 | 5.295 |
| S140 | 2 | 139.5 | 0.079 | 5.492 |
| S145 | 2 | 144.5 | 0.079 | 5.689 |
| S150 | 2 | 149.5 | 0.079 | 5.886 |
| P10A | 2.4 | 9.8 | 0.094 | 0.386 |
| P11 | 2.4 | 10.8 | 0.094 | 0.425 |
| P11.2 | 2.4 | 11 | 0.094 | 0.433 |
| P12 | 2.4 | 11.8 | 0.094 | 0.465 |
| P12.5 | 2.4 | 12.3 | 0.094 | 0.484 |
| P13 | 2.4 | 12.8 | 0.094 | 0.504 |
| P14 | 2.4 | 13.8 | 0.094 | 0.543 |
| P15 | 2.4 | 14.8 | 0.094 | 0.583 |
| P16 | 2.4 | 15.8 | 0.094 | 0.622 |
| P17 | 2.4 | 16.8 | 0.094 | 0.661 |
| P18 | 2.4 | 17.8 | 0.094 | 0.701 |
| P19 | 2.4 | 18.8 | 0.094 | 0.74 |
| P20 | 2.4 | 19.8 | 0.094 | 0.78 |
| P21 | 2.4 | 20.8 | 0.094 | 0.819 |
| P22 | 2.4 | 21.8 | 0.094 | 0.858 |
| G25 | 3.1 | 24.4 | 0.122 | 0.961 |
| G30 | 3.1 | 29.4 | 0.122 | 1.157 |
| G35 | 3.1 | 34.4 | 0.122 | 1.354 |
| G40 | 3.1 | 39.4 | 0.122 | 1.551 |
| G45 | 3.1 | 44.4 | 0.122 | 1.748 |
| G50 | 3.1 | 49.4 | 0.122 | 1.945 |
| G55 | 3.1 | 54.4 | 0.122 | 2.142 |
| G60 | 3.1 | 59.4 | 0.122 | 2.339 |
| G65 | 3.1 | 64.4 | 0.122 | 2.535 |
| G70 | 3.1 | 69.4 | 0.122 | 2.732 |
| G75 | 3.1 | 74.4 | 0.122 | 2.929 |
| G80 | 3.1 | 79.4 | 0.122 | 3.126 |
| G85 | 3.1 | 84.4 | 0.122 | 3.323 |
| G90 | 3.1 | 89.4 | 0.122 | 3.52 |
| G95 | 3.1 | 94.4 | 0.122 | 3.717 |
| G100 | 3.1 | 99.4 | 0.122 | 3.913 |
| G105 | 3.1 | 104.4 | 0.122 | 4.11 |
| G110 | 3.1 | 109.4 | 0.122 | 4.307 |
| G115 | 3.1 | 114.4 | 0.122 | 4.504 |
| G120 | 3.1 | 119.4 | 0.122 | 4.701 |
| G125 | 3.1 | 124.4 | 0.122 | 4.898 |
| G130 | 3.1 | 129.4 | 0.122 | 5.094 |
| G135 | 3.1 | 134.4 | 0.122 | 5.291 |
| G140 | 3.1 | 139.4 | 0.122 | 5.488 |
| G145 | 3.1 | 144.4 | 0.122 | 5.685 |
| P22A | 3.5 | 21.7 | 0.138 | 0.854 |
| P22.4 | 3.5 | 22.1 | 0.138 | 0.87 |
| P24 | 3.5 | 23.7 | 0.138 | 0.933 |
| P25 | 3.5 | 24.7 | 0.138 | 0.972 |
| P25.5 | 3.5 | 25.2 | 0.138 | 0.992 |
| P26 | 3.5 | 25.7 | 0.138 | 1.012 |
| P28 | 3.5 | 27.7 | 0.138 | 1.091 |
| P29 | 3.5 | 28.7 | 0.138 | 1.13 |
| P29.5 | 3.5 | 29.2 | 0.138 | 1.15 |
| P30 | 3.5 | 29.7 | 0.138 | 1.169 |
| P31 | 3.5 | 30.7 | 0.138 | 1.209 |
| P31.5 | 3.5 | 31.2 | 0.138 | 1.228 |
| P32 | 3.5 | 31.7 | 0.138 | 1.248 |
| P33 | 3.5 | 32.7 | 0.138 | 1.287 |
| P34 | 3.5 | 33.7 | 0.138 | 1.327 |
| P35 | 3.5 | 34.7 | 0.138 | 1.366 |
| P35.5 | 3.5 | 35.2 | 0.138 | 1.386 |
| P36 | 3.5 | 35.7 | 0.138 | 1.406 |
| P38 | 3.5 | 37.7 | 0.138 | 1.484 |
| P39 | 3.5 | 38.7 | 0.138 | 1.524 |
| P40 | 3.5 | 39.7 | 0.138 | 1.563 |
| P41 | 3.5 | 40.7 | 0.138 | 1.602 |
| P42 | 3.5 | 41.7 | 0.138 | 1.642 |
| P44 | 3.5 | 43.7 | 0.138 | 1.72 |
| P45 | 3.5 | 44.7 | 0.138 | 1.76 |
| P46 | 3.5 | 45.7 | 0.138 | 1.799 |
| P48 | 3.5 | 47.7 | 0.138 | 1.878 |
| P49 | 3.5 | 48.7 | 0.138 | 1.917 |
| P50 | 3.5 | 49.7 | 0.138 | 1.957 |
| V15 | 4 | 14.5 | 0.157 | 0.571 |
| V24 | 4 | 23.5 | 0.157 | 0.925 |
| V34 | 4 | 33.5 | 0.157 | 1.319 |
| V40 | 4 | 39.5 | 0.157 | 1.555 |
| V55 | 4 | 54.5 | 0.157 | 2.146 |
| V70 | 4 | 69 | 0.157 | 2.717 |
| V85 | 4 | 84 | 0.157 | 3.307 |
| V100 | 4 | 99 | 0.157 | 3.898 |
| V120 | 4 | 119 | 0.157 | 4.685 |
| V150 | 4 | 148.5 | 0.157 | 5.846 |
| V175 | 4 | 173 | 0.157 | 6.811 |
| P48A | 5.7 | 47.6 | 0.224 | 1.874 |
| P50A | 5.7 | 49.6 | 0.224 | 1.953 |
| P52 | 5.7 | 51.6 | 0.224 | 2.031 |
| P53 | 5.7 | 52.6 | 0.224 | 2.071 |
| P55 | 5.7 | 54.6 | 0.224 | 2.15 |
| P56 | 5.7 | 55.6 | 0.224 | 2.189 |
| P58 | 5.7 | 57.6 | 0.224 | 2.268 |
| P60 | 5.7 | 59.6 | 0.224 | 2.346 |
| P62 | 5.7 | 61.6 | 0.224 | 2.425 |
| P63 | 5.7 | 62.6 | 0.224 | 2.465 |
| P65 | 5.7 | 64.6 | 0.224 | 2.543 |
| P67 | 5.7 | 66.6 | 0.224 | 2.622 |
| P70 | 5.7 | 69.6 | 0.224 | 2.74 |
| P71 | 5.7 | 70.6 | 0.224 | 2.78 |
| P75 | 5.7 | 74.6 | 0.224 | 2.937 |
| P80 | 5.7 | 79.6 | 0.224 | 3.134 |
| P85 | 5.7 | 84.6 | 0.224 | 3.331 |
| P90 | 5.7 | 89.6 | 0.224 | 3.528 |
| P95 | 5.7 | 94.6 | 0.224 | 3.724 |
| P100 | 5.7 | 99.6 | 0.224 | 3.921 |
| P102 | 5.7 | 101.6 | 0.224 | 4 |
| P105 | 5.7 | 104.6 | 0.224 | 4.118 |
| P110 | 5.7 | 109.6 | 0.224 | 4.315 |
| P112 | 5.7 | 111.6 | 0.224 | 4.394 |
| P115 | 5.7 | 114.6 | 0.224 | 4.512 |
| P120 | 5.7 | 119.6 | 0.224 | 4.709 |
| P125 | 5.7 | 124.6 | 0.224 | 4.906 |
| P130 | 5.7 | 129.6 | 0.224 | 5.102 |
| P132 | 5.7 | 131.6 | 0.224 | 5.181 |
| P135 | 5.7 | 134.6 | 0.224 | 5.299 |
| P140 | 5.7 | 139.6 | 0.224 | 5.496 |
| P145 | 5.7 | 144.6 | 0.224 | 5.693 |
| G150 | 5.7 | 149.3 | 0.224 | 5.878 |
| P150 | 5.7 | 149.6 | 0.224 | 5.89 |
| G155 | 5.7 | 154.3 | 0.224 | 6.075 |
| G160 | 5.7 | 159.3 | 0.224 | 6.272 |
| G165 | 5.7 | 164.3 | 0.224 | 6.469 |
| G170 | 5.7 | 169.3 | 0.224 | 6.665 |
| G175 | 5.7 | 174.3 | 0.224 | 6.862 |
| G180 | 5.7 | 179.3 | 0.224 | 7.059 |
| G185 | 5.7 | 184.3 | 0.224 | 7.256 |
| G190 | 5.7 | 189.3 | 0.224 | 7.453 |
| G195 | 5.7 | 194.3 | 0.224 | 7.65 |
| G200 | 5.7 | 199.3 | 0.224 | 7.846 |
| G205 | 5.7 | 204.3 | 0.224 | 8.043 |
| G210 | 5.7 | 209.3 | 0.224 | 8.24 |
| G215 | 5.7 | 214.3 | 0.224 | 8.437 |
| G220 | 5.7 | 219.3 | 0.224 | 8.634 |
| G225 | 5.7 | 224.3 | 0.224 | 8.831 |
| G230 | 5.7 | 229.3 | 0.224 | 9.028 |
| G235 | 5.7 | 234.3 | 0.224 | 9.224 |
| G240 | 5.7 | 239.3 | 0.224 | 9.421 |
| G245 | 5.7 | 244.3 | 0.224 | 9.618 |
| G250 | 5.7 | 249.3 | 0.224 | 9.815 |
| G255 | 5.7 | 254.3 | 0.224 | 10.012 |
| G260 | 5.7 | 259.3 | 0.224 | 10.209 |
| G265 | 5.7 | 264.3 | 0.224 | 10.406 |
| G270 | 5.7 | 269.3 | 0.224 | 10.602 |
| G280 | 5.7 | 279.3 | 0.224 | 10.996 |
| G285 | 5.7 | 284.3 | 0.224 | 11.193 |
| G290 | 5.7 | 289.3 | 0.224 | 11.39 |
| G300 | 5.7 | 299.3 | 0.224 | 11.783 |
| G305 | 5.7 | 304.3 | 0.224 | 11.98 |
| G310 | 5.7 | 309.3 | 0.224 | 12.177 |
| G315 | 5.7 | 314.3 | 0.224 | 12.374 |
| G320 | 5.7 | 319.3 | 0.224 | 12.571 |
| G325 | 5.7 | 324.3 | 0.224 | 12.768 |
| G330 | 5.7 | 329.3 | 0.224 | 12.965 |
| G335 | 5.7 | 334.3 | 0.224 | 13.161 |
| G340 | 5.7 | 339.3 | 0.224 | 13.358 |
| G345 | 5.7 | 344.3 | 0.224 | 13.555 |
| G350 | 5.7 | 349.3 | 0.224 | 13.752 |
| G355 | 5.7 | 354.3 | 0.224 | 13.949 |
| G360 | 5.7 | 359.3 | 0.224 | 14.146 |
| G365 | 5.7 | 364.3 | 0.224 | 14.343 |
| G370 | 5.7 | 369.3 | 0.224 | 14.539 |
| G375 | 5.7 | 374.3 | 0.224 | 14.736 |
| G380 | 5.7 | 379.3 | 0.224 | 14.933 |
| G385 | 5.7 | 384.3 | 0.224 | 15.13 |
| G390 | 5.7 | 389.3 | 0.224 | 15.327 |
| G395 | 5.7 | 394.3 | 0.224 | 15.524 |
| G400 | 5.7 | 399.3 | 0.224 | 15.72 |
| G405 | 5.7 | 404.3 | 0.224 | 15.917 |
| G410 | 5.7 | 409.3 | 0.224 | 16.114 |
| G415 | 5.7 | 414.3 | 0.224 | 16.311 |
| G420 | 5.7 | 419.3 | 0.224 | 16.508 |
| G425 | 5.7 | 424.3 | 0.224 | 16.705 |
| G430 | 5.7 | 429.3 | 0.224 | 16.902 |
| G435 | 5.7 | 435.3 | 0.224 | 17.138 |
| G440 | 5.7 | 439.3 | 0.224 | 17.295 |
| G445 | 5.7 | 444.3 | 0.224 | 17.492 |
| G450 | 5.7 | 449.3 | 0.224 | 17.689 |
| G455 | 5.7 | 454.3 | 0.224 | 17.886 |
| G460 | 5.7 | 459.3 | 0.224 | 18.083 |
| G465 | 5.7 | 464.3 | 0.224 | 18.28 |
| G470 | 5.7 | 469.3 | 0.224 | 18.476 |
| G475 | 5.7 | 474.3 | 0.224 | 18.673 |
| G480 | 5.7 | 479.3 | 0.224 | 18.87 |
| G485 | 5.7 | 484.3 | 0.224 | 19.067 |
| G490 | 5.7 | 489.3 | 0.224 | 19.264 |
| G495 | 5.7 | 494.3 | 0.224 | 19.461 |
| G500 | 5.7 | 499.3 | 0.224 | 19.657 |
| G510 | 5.7 | 509.3 | 0.224 | 20.051 |
| G520 | 5.7 | 519.3 | 0.224 | 20.445 |
| V225 | 6 | 222.5 | 0.236 | 8.76 |
| V275 | 6 | 272 | 0.236 | 10.709 |
| V325 | 6 | 321.5 | 0.236 | 12.657 |
| V380 | 6 | 376 | 0.236 | 14.803 |
| V430 | 6 | 425.5 | 0.236 | 16.752 |
| P150A | 8.4 | 149.5 | 0.331 | 5.886 |
| P155 | 8.4 | 154.5 | 0.331 | 6.083 |
| P160 | 8.4 | 159.5 | 0.331 | 6.28 |
| P165 | 8.4 | 164.5 | 0.331 | 6.476 |
| P170 | 8.4 | 169.5 | 0.331 | 6.673 |
| P175 | 8.4 | 174.5 | 0.331 | 6.87 |
| P180 | 8.4 | 179.5 | 0.331 | 7.067 |
| P185 | 8.4 | 184.5 | 0.331 | 7.264 |
| P190 | 8.4 | 189.5 | 0.331 | 7.461 |
| P195 | 8.4 | 194.5 | 0.331 | 7.657 |
| P200 | 8.4 | 199.5 | 0.331 | 7.854 |
| P205 | 8.4 | 204.5 | 0.331 | 8.051 |
| P209 | 8.4 | 208.5 | 0.331 | 8.209 |
| P210 | 8.4 | 209.5 | 0.331 | 8.248 |
| P215 | 8.4 | 214.5 | 0.331 | 8.445 |
| P220 | 8.4 | 219.5 | 0.331 | 8.642 |
| P225 | 8.4 | 224.5 | 0.331 | 8.839 |
| P230 | 8.4 | 229.5 | 0.331 | 9.035 |
| P235 | 8.4 | 234.5 | 0.331 | 9.232 |
| P240 | 8.4 | 239.5 | 0.331 | 9.429 |
| P245 | 8.4 | 244.5 | 0.331 | 9.626 |
| P250 | 8.4 | 249.5 | 0.331 | 9.823 |
| P255 | 8.4 | 254.5 | 0.331 | 10.02 |
| P260 | 8.4 | 259.5 | 0.331 | 10.217 |
| P265 | 8.4 | 264.5 | 0.331 | 10.413 |
| P270 | 8.4 | 269.5 | 0.331 | 10.61 |
| P275 | 8.4 | 274.5 | 0.331 | 10.807 |
| P280 | 8.4 | 279.5 | 0.331 | 11.004 |
| P285 | 8.4 | 284.5 | 0.331 | 11.201 |
| P290 | 8.4 | 289.5 | 0.331 | 11.398 |
| P295 | 8.4 | 294.5 | 0.331 | 11.594 |
| P300 | 8.4 | 299.5 | 0.331 | 11.791 |
| P305 | 8.4 | 304.5 | 0.331 | 11.988 |
| P310 | 8.4 | 309.5 | 0.331 | 12.185 |
| P315 | 8.4 | 314.5 | 0.331 | 12.382 |
| P320 | 8.4 | 319.5 | 0.331 | 12.579 |
| P335 | 8.4 | 334.5 | 0.331 | 13.169 |
| P340 | 8.4 | 339.5 | 0.331 | 13.366 |
| P350 | 8.4 | 349.5 | 0.331 | 13.76 |
| P355 | 8.4 | 354.5 | 0.331 | 13.957 |
| P360 | 8.4 | 359.5 | 0.331 | 14.154 |
| P375 | 8.4 | 374.5 | 0.331 | 14.744 |
| P380 | 8.4 | 379.5 | 0.331 | 14.941 |
| P385 | 8.4 | 384.5 | 0.331 | 15.138 |
| P390 | 8.4 | 389.5 | 0.331 | 15.335 |
| P400 | 8.4 | 399.5 | 0.331 | 15.728 |
| P410 | 8.4 | 409.5 | 0.331 | 16.122 |
| P420 | 8.4 | 419.5 | 0.331 | 16.516 |
| P440 | 8.4 | 439.5 | 0.331 | 17.303 |
| P450 | 8.4 | 449.5 | 0.331 | 17.697 |
| P470 | 8.4 | 469.5 | 0.331 | 18.484 |
| P480 | 8.4 | 479.5 | 0.331 | 18.878 |
| V480 | 10 | 475 | 0.394 | 18.701 |
| V530 | 10 | 524.5 | 0.394 | 20.65 |
| V585 | 10 | 579 | 0.394 | 22.795 |
| V640 | 10 | 633.5 | 0.394 | 24.941 |
| V690 | 10 | 683 | 0.394 | 26.89 |
| V740 | 10 | 732.5 | 0.394 | 28.839 |
| V790 | 10 | 782 | 0.394 | 30.787 |
| V845 | 10 | 836.5 | 0.394 | 32.933 |
| V950 | 10 | 940.5 | 0.394 | 37.028 |
| V1055 | 10 | 1044 | 0.394 | 41.102 |
JIS – P Series
| Reference | C/S (MM) | I.D. (Inch) |
|---|---|---|
| P3 | 1.9 | 2.8 |
| P4 | 1.9 | 3.8 |
| P5 | 1.9 | 4.8 |
| P6 | 1.9 | 5.8 |
| P7 | 1.9 | 6.8 |
| P8 | 1.9 | 7.8 |
| P9 | 1.9 | 8.8 |
| P10 | 1.9 | 9.8 |
| P10A | 2.4 | 9.8 |
| P11 | 2.4 | 10.8 |
| P11.2 | 2.4 | 11 |
| P12 | 2.4 | 11.8 |
| P12.5 | 2.4 | 12.3 |
| P13 | 2.4 | 12.8 |
| P14 | 2.4 | 13.8 |
| P15 | 2.4 | 14.8 |
| P16 | 2.4 | 15.8 |
| P17 | 2.4 | 16.8 |
| P18 | 2.4 | 17.8 |
| P19 | 2.4 | 18.8 |
| P20 | 2.4 | 19.8 |
| P21 | 2.4 | 20.8 |
| P22A | 3.5 | 21.7 |
| P22 | 2.4 | 21.8 |
| P22.4 | 3.5 | 22.1 |
| P24 | 3.5 | 23.7 |
| P25 | 3.5 | 24.7 |
| P25.5 | 3.5 | 25.2 |
| P26 | 3.5 | 25.7 |
| P28 | 3.5 | 27.7 |
| P29 | 3.5 | 28.7 |
| P29.5 | 3.5 | 29.2 |
| P30 | 3.5 | 29.7 |
| P31 | 3.5 | 30.7 |
| P31.5 | 3.5 | 31.2 |
| P32 | 3.5 | 31.7 |
| P33 | 3.5 | 32.7 |
| P34 | 3.5 | 33.7 |
| P35 | 3.5 | 34.7 |
| P35.5 | 3.5 | 35.2 |
| P36 | 3.5 | 35.7 |
| P38 | 3.5 | 37.7 |
| P39 | 3.5 | 38.7 |
| P40 | 3.5 | 39.7 |
| P41 | 3.5 | 40.7 |
| P42 | 3.5 | 41.7 |
| P44 | 3.5 | 43.7 |
| P45 | 3.5 | 44.7 |
| P46 | 3.5 | 45.7 |
| P48A | 5.7 | 47.6 |
| P48 | 3.5 | 47.7 |
| P49 | 3.5 | 48.7 |
| P50A | 5.7 | 49.6 |
| P50 | 3.5 | 49.7 |
| P52 | 5.7 | 51.6 |
| P53 | 5.7 | 52.6 |
| P55 | 5.7 | 54.6 |
| P56 | 5.7 | 55.6 |
| P58 | 5.7 | 57.6 |
| P60 | 5.7 | 59.6 |
| P62 | 5.7 | 61.6 |
| P63 | 5.7 | 62.6 |
| P65 | 5.7 | 64.6 |
| P67 | 5.7 | 66.6 |
| P70 | 5.7 | 69.6 |
| P71 | 5.7 | 70.6 |
| P75 | 5.7 | 74.6 |
| P80 | 5.7 | 79.6 |
| P85 | 5.7 | 84.6 |
| P90 | 5.7 | 89.6 |
| P95 | 5.7 | 94.6 |
| P100 | 5.7 | 99.6 |
| P102 | 5.7 | 101.6 |
| P105 | 5.7 | 104.6 |
| P110 | 5.7 | 109.6 |
| P112 | 5.7 | 111.6 |
| P115 | 5.7 | 114.6 |
| P120 | 5.7 | 119.6 |
| P125 | 5.7 | 124.6 |
| P130 | 5.7 | 129.6 |
| P132 | 5.7 | 131.6 |
| P135 | 5.7 | 134.6 |
| P140 | 5.7 | 139.6 |
| P145 | 5.7 | 144.6 |
| P150A | 8.4 | 149.5 |
| P150 | 5.7 | 149.6 |
| P155 | 8.4 | 154.5 |
| P160 | 8.4 | 159.5 |
| P165 | 8.4 | 164.5 |
| P170 | 8.4 | 169.5 |
| P175 | 8.4 | 174.5 |
| P180 | 8.4 | 179.5 |
| P185 | 8.4 | 184.5 |
| P190 | 8.4 | 189.5 |
| P195 | 8.4 | 194.5 |
| P200 | 8.4 | 199.5 |
| P205 | 8.4 | 204.5 |
| P209 | 8.4 | 208.5 |
| P210 | 8.4 | 209.5 |
| P215 | 8.4 | 214.5 |
| P220 | 8.4 | 219.5 |
| P225 | 8.4 | 224.5 |
| P230 | 8.4 | 229.5 |
| P235 | 8.4 | 234.5 |
| P240 | 8.4 | 239.5 |
| P245 | 8.4 | 244.5 |
| P250 | 8.4 | 249.5 |
| P255 | 8.4 | 254.5 |
| P260 | 8.4 | 259.5 |
| P265 | 8.4 | 264.5 |
| P270 | 8.4 | 269.5 |
| P275 | 8.4 | 274.5 |
| P280 | 8.4 | 279.5 |
| P285 | 8.4 | 284.5 |
| P290 | 8.4 | 289.5 |
| P295 | 8.4 | 294.5 |
| P300 | 8.4 | 299.5 |
| P305 | 8.4 | 304.5 |
| P310 | 8.4 | 309.5 |
| P315 | 8.4 | 314.5 |
| P320 | 8.4 | 319.5 |
| P335 | 8.4 | 334.5 |
| P340 | 8.4 | 339.5 |
| P350 | 8.4 | 349.5 |
| P355 | 8.4 | 354.5 |
| P360 | 8.4 | 359.5 |
| P375 | 8.4 | 374.5 |
| P380 | 8.4 | 379.5 |
| P385 | 8.4 | 384.5 |
| P390 | 8.4 | 389.5 |
| P400 | 8.4 | 399.5 |
| P410 | 8.4 | 409.5 |
| P420 | 8.4 | 419.5 |
| P440 | 8.4 | 439.5 |
| P450 | 8.4 | 449.5 |
| P470 | 8.4 | 469.5 |
| P480 | 8.4 | 479.5 |
JIS – G Series
| Reference | C/S (MM) | I.D. (Inch) |
|---|---|---|
| G25 | 3.1 | 24.4 |
| G30 | 3.1 | 29.4 |
| G35 | 3.1 | 34.4 |
| G40 | 3.1 | 39.4 |
| G45 | 3.1 | 44.4 |
| G50 | 3.1 | 49.4 |
| G55 | 3.1 | 54.4 |
| G60 | 3.1 | 59.4 |
| G65 | 3.1 | 64.4 |
| G70 | 3.1 | 69.4 |
| G75 | 3.1 | 74.4 |
| G80 | 3.1 | 79.4 |
| G85 | 3.1 | 84.4 |
| G90 | 3.1 | 89.4 |
| G95 | 3.1 | 94.4 |
| G100 | 3.1 | 99.4 |
| G105 | 3.1 | 104.4 |
| G110 | 3.1 | 109.4 |
| G115 | 3.1 | 114.4 |
| G120 | 3.1 | 119.4 |
| G125 | 3.1 | 124.4 |
| G130 | 3.1 | 129.4 |
| G135 | 3.1 | 134.4 |
| G140 | 3.1 | 139.4 |
| G145 | 3.1 | 144.4 |
| G150 | 5.7 | 149.3 |
| G155 | 5.7 | 154.3 |
| G160 | 5.7 | 159.3 |
| G165 | 5.7 | 164.3 |
| G170 | 5.7 | 169.3 |
| G175 | 5.7 | 174.3 |
| G180 | 5.7 | 179.3 |
| G185 | 5.7 | 184.3 |
| G190 | 5.7 | 189.3 |
| G195 | 5.7 | 194.3 |
| G200 | 5.7 | 199.3 |
| G205 | 5.7 | 204.3 |
| G210 | 5.7 | 209.3 |
| G215 | 5.7 | 214.3 |
| G220 | 5.7 | 219.3 |
| G225 | 5.7 | 224.3 |
| G230 | 5.7 | 229.3 |
| G235 | 5.7 | 234.3 |
| G240 | 5.7 | 239.3 |
| G245 | 5.7 | 244.3 |
| G250 | 5.7 | 249.3 |
| G255 | 5.7 | 254.3 |
| G260 | 5.7 | 259.3 |
| G265 | 5.7 | 264.3 |
| G270 | 5.7 | 269.3 |
| G280 | 5.7 | 279.3 |
| G285 | 5.7 | 284.3 |
| G290 | 5.7 | 289.3 |
| G300 | 5.7 | 299.3 |
| G305 | 5.7 | 304.3 |
| G310 | 5.7 | 309.3 |
| G315 | 5.7 | 314.3 |
| G320 | 5.7 | 319.3 |
| G325 | 5.7 | 324.3 |
| G330 | 5.7 | 329.3 |
| G335 | 5.7 | 334.3 |
| G340 | 5.7 | 339.3 |
| G345 | 5.7 | 344.3 |
| G350 | 5.7 | 349.3 |
| G355 | 5.7 | 354.3 |
| G360 | 5.7 | 359.3 |
| G365 | 5.7 | 364.3 |
| G370 | 5.7 | 369.3 |
| G375 | 5.7 | 374.3 |
| G380 | 5.7 | 379.3 |
| G385 | 5.7 | 384.3 |
| G390 | 5.7 | 389.3 |
| G395 | 5.7 | 394.3 |
| G400 | 5.7 | 399.3 |
| G405 | 5.7 | 404.3 |
| G410 | 5.7 | 409.3 |
| G415 | 5.7 | 414.3 |
| G420 | 5.7 | 419.3 |
| G425 | 5.7 | 424.3 |
| G430 | 5.7 | 429.3 |
| G435 | 5.7 | 435.3 |
| G440 | 5.7 | 439.3 |
| G445 | 5.7 | 444.3 |
| G450 | 5.7 | 449.3 |
| G455 | 5.7 | 454.3 |
| G460 | 5.7 | 459.3 |
| G465 | 5.7 | 464.3 |
| G470 | 5.7 | 469.3 |
| G475 | 5.7 | 474.3 |
| G480 | 5.7 | 479.3 |
| G485 | 5.7 | 484.3 |
| G490 | 5.7 | 489.3 |
| G495 | 5.7 | 494.3 |
| G500 | 5.7 | 499.3 |
| G510 | 5.7 | 509.3 |
| G520 | 5.7 | 519.3 |
JIS – S Series
| Reference | C/S (MM) | I.D. (Inch) |
|---|---|---|
| S3 | 1.5 | 2.5 |
| S4 | 1.5 | 3.5 |
| S5 | 1.5 | 4.5 |
| S6 | 1.5 | 5.5 |
| S7 | 1.5 | 6.5 |
| S8 | 1.5 | 7.5 |
| S9 | 1.5 | 8.5 |
| S10 | 1.5 | 9.5 |
| S11.2 | 1.5 | 10.7 |
| S12 | 1.5 | 11.5 |
| S12.5 | 1.5 | 12 |
| S14 | 1.5 | 13.5 |
| S15 | 1.5 | 14.5 |
| S16 | 1.5 | 15.5 |
| S18 | 1.5 | 17.5 |
| S20 | 1.5 | 19.5 |
| S22 | 1.5 | 21.5 |
| S22.4 | 2 | 21.9 |
| S24 | 2 | 23.5 |
| S25 | 2 | 24.5 |
| S26 | 2 | 25.5 |
| S28 | 2 | 27.5 |
| S29 | 2 | 28.5 |
| S30 | 2 | 29.5 |
| S31.5 | 2 | 31 |
| S32 | 2 | 31.5 |
| S34 | 2 | 33.5 |
| S35 | 2 | 34.5 |
| S35.5 | 2 | 35 |
| S36 | 2 | 35.5 |
| S38 | 2 | 37.5 |
| S39 | 2 | 38.5 |
| S40 | 2 | 39.5 |
| S42 | 2 | 41.5 |
| S44 | 2 | 43.5 |
| S45 | 2 | 44.5 |
| S46 | 2 | 45.5 |
| S48 | 2 | 47.5 |
| S50 | 2 | 49.5 |
| S53 | 2 | 52.5 |
| S55 | 2 | 54.5 |
| S56 | 2 | 55.5 |
| S60 | 2 | 59.5 |
| S63 | 2 | 62.5 |
| S65 | 2 | 64.5 |
| S67 | 2 | 66.5 |
| S70 | 2 | 69.5 |
| S71 | 2 | 70.5 |
| S75 | 2 | 74.5 |
| S80 | 2 | 79.5 |
| S85 | 2 | 84.5 |
| S90 | 2 | 89.5 |
| S95 | 2 | 94.5 |
| S100 | 2 | 99.5 |
| S105 | 2 | 104.5 |
| S110 | 2 | 109.5 |
| S112 | 2 | 111.5 |
| S115 | 2 | 114.5 |
| S120 | 2 | 119.5 |
| S125 | 2 | 124.5 |
| S130 | 2 | 129.5 |
| S132 | 2 | 131.5 |
| S135 | 2 | 134.5 |
| S140 | 2 | 139.5 |
| S145 | 2 | 144.5 |
| S150 | 2 | 149.5 |
JIS – V Series
| Reference | C/S (MM) | I.D. (Inch) |
|---|---|---|
| V15 | 4 | 14.5 |
| V24 | 4 | 23.5 |
| V34 | 4 | 33.5 |
| V40 | 4 | 39.5 |
| V55 | 4 | 54.5 |
| V70 | 4 | 69 |
| V85 | 4 | 84 |
| V100 | 4 | 99 |
| V120 | 4 | 119 |
| V150 | 4 | 148.5 |
| V175 | 4 | 173 |
| V225 | 6 | 222.5 |
| V275 | 6 | 272 |
| V325 | 6 | 321.5 |
| V380 | 6 | 376 |
| V430 | 6 | 425.5 |
| V480 | 10 | 475 |
| V530 | 10 | 524.5 |
| V585 | 10 | 579 |
| V640 | 10 | 633.5 |
| V690 | 10 | 683 |
| V740 | 10 | 732.5 |
| V790 | 10 | 782 |
| V845 | 10 | 836.5 |
| V950 | 10 | 940.5 |
| V1055 | 10 | 1044 |
What Are JIS B 2401 Metric O-Rings?
JIS B 2401 is a Japanese industrial standard that defines O-ring dimensions, including inside diameter and cross-section requirements for different sealing applications.
Unlike general metric O-rings that may only follow dimensional measurements, JIS B 2401 sizes are organized according to specific operating conditions and sealing functions.
The standard includes several series:
JIS P Series — Dynamic Applications
Designed for applications where the O-ring experiences movement.
Typical uses:
- Hydraulic cylinders
- Pneumatic actuators
- Moving piston applications
- Reciprocating equipment
P Series O-rings are selected when controlled friction and wear resistance are required.
JIS G Series — Static Applications
Designed for fixed sealing applications.
Common uses:
- Hydraulic ports
- Flanges
- Covers
- Machinery housings
G Series O-rings provide reliable sealing where the seal remains stationary after installation.
JIS S Series — Special Sizes
S Series includes special dimension combinations for applications that require sizes outside common standard selections.
Used in:
- Custom equipment
- Replacement parts
- Specialized industrial systems
JIS V Series — Vacuum Flange Applications
V Series O-rings are designed specifically for vacuum sealing applications.
Typical applications:
- Vacuum chambers
- Semiconductor equipment
- Vacuum processing systems
These sizes help maintain stable sealing performance where leakage prevention is critical.
Why Choose JIS B 2401 O-Rings?
Accurate Fit for Japanese Equipment
Many Japanese OEM machines are designed around JIS dimensions. Using a similar but non-standard metric size may create problems such as:
- Improper compression
- Seal extrusion
- Leakage under pressure
- Difficult installation
Matching the original JIS specification helps maintain the intended groove design and sealing performance.
Better Compatibility with Existing Equipment
JIS B 2401 O-rings are widely used in:
- Japanese hydraulic machinery
- Automotive components
- Manufacturing equipment
- Industrial automation systems
- Imported replacement equipment
For maintenance teams, selecting the correct JIS size simplifies replacement and reduces equipment downtime.
Common Materials for JIS Metric O-Rings
The correct size alone does not guarantee sealing reliability. Material selection must match the operating environment.
NBR (Nitrile Rubber)
Suitable for:
- Hydraulic oil
- Lubricants
- General industrial equipment
Advantages:
- Good oil resistance
- Cost-effective
- Widely used in hydraulic applications
FKM (Viton®)
Recommended for:
- High-temperature systems
- Fuels
- Chemical environments
Advantages:
- Excellent heat resistance
- Superior chemical compatibility
- Long service life in demanding conditions
EPDM
Suitable for:
- Water systems
- Steam applications
- Coolant environments
Advantages:
- Excellent water resistance
- Good weather aging performance
Silicone (VMQ)
Used for:
- Food equipment
- Medical applications
- Low-temperature environments
Advantages:
- Excellent flexibility
- Wide temperature capability
JIS B 2401 vs Other O-Ring Standards
Engineers often need to determine whether JIS, ISO, or AS568 sizes are interchangeable.
| Standard | Typical Application |
|---|---|
| JIS B 2401 | Japanese industrial equipment |
| ISO 3601 | International metric O-rings |
| AS568 | North American inch-based O-rings |
Although some sizes may appear similar, differences in cross-section and inside diameter can affect compression and sealing performance.
For critical applications, replacing a JIS O-ring with another standard should always be verified by checking:
- Groove dimensions
- Compression percentage
- Pressure conditions
- Operating media
How to Select the Correct JIS O-Ring
Before ordering replacement O-rings, confirm:
1. Identify the Standard
Determine whether the equipment requires:
- JIS B 2401
- ISO metric
- AS568
2. Confirm Dimensions
Measure:
- Inside diameter (ID)
- Cross-section diameter (CS)
- Groove dimensions
3. Match the Material
Consider:
- Temperature range
- Chemical exposure
- Pressure conditions
- Motion requirements
4. Check Application Type
Select the correct series:
- P Series → Dynamic sealing
- G Series → Static sealing
- V Series → Vacuum applications
Improve Sealing Reliability with the Correct JIS Standard O-Ring
JIS B 2401 Metric O-Rings provide a reliable sealing solution for equipment designed around Japanese industrial standards. By selecting the correct series, dimensions, and elastomer material, engineers can achieve better sealing performance, reduce leakage risks, and extend equipment service life.
For Japanese machinery, hydraulic systems, automotive components, and precision industrial equipment, using the correct JIS specification is an important step toward maintaining original equipment performance.