O-Rings
Additional Information
There are several different standards to choose from when it comes to O-ring dimensions. The most popular in the United States is the AS568 standard for O-ring sizes and tolerances. Maintained by the Society of Automotive Engineers, this standard allows the user to choose from five different cross-sections with inside diameters ranging from 1/32" to 26". Tube fitting boss seals are included in AS568 as 900 series O-ring sizes, and are intended for use in MS33649 (now superseded by SAE-AS5202) straight thread tube fitings. RT/Dygert also offers a wide array of metric sizes, in both standard and non-standard dimensions. As a subset of the metric sizes offered, we also stock many Japanese Industrial Standard (JIS B2401) sizes. If an O-ring with special size or fluid resistance is required, RT/Dygert can provide custom O-rings, specially made to your demanding requirements.
SIZES
| Dimensions in Inches | Nominal Size (Reference Only) | |||||||
| ID | AS568A | I.D. | ± | C/S | Vol (in3) | I.D. | O.D. | C/S |
| 1484 | 425 | 4.475 | .033 | .275 ± .006 | .8863 | 4-1/2 | 5 | 1/4 |
| 1485 | 426 | 4.6 | .033 | .275 ± .006 | .9097 | 4-5/8 | 5-1/8 | 1/4 |
| 1486 | 427 | 4.725 | .033 | .275 ± .006 | .9330 | 4-3/4 | 5-1/4 | 1/4 |
| 1487 | 428 | 4.85 | .033 | .275 ± .006 | .9563 | 4-7/8 | 5-3/8 | 1/4 |
| 1488 | 429 | 4.975 | .037 | .275 ± .006 | .9796 | 5 | 5-1/2 | 1/4 |
| 1489 | 430 | 5.1 | .037 | .275 ± .006 | 1.0030 | 5-1/8 | 5-5/8 | 1/4 |
| 1490 | 431 | 5.225 | .037 | .275 ± .006 | 1.0263 | 5-1/4 | 5-3/4 | 1/4 |
| 1491 | 432 | 5.35 | .037 | .275 ± .006 | 1.0496 | 5-3/8 | 5-7/8 | 1/4 |
| 1492 | 433 | 5.475 | .037 | .275 ± .006 | 1.0729 | 5-1/2 | 6 | 1/4 |
| 1493 | 434 | 5.6 | .037 | .275 ± .006 | 1.0962 | 5-5/8 | 6-1/8 | 1/4 |
| 1494 | 435 | 5.725 | .037 | .275 ± .006 | 1.1196 | 5-3/4 | 6-1/4 | 1/4 |
| 1495 | 436 | 5.85 | .037 | .275 ± .006 | 1.1429 | 5-7/8 | 6-3/8 | 1/4 |
| 1496 | 437 | 5.975 | .037 | .275 ± .006 | 1.1662 | 6 | 6-1/2 | 1/4 |
| 1497 | 438 | 6.225 | .040 | .275 ± .006 | 1.2129 | 6-1/4 | 6-3/4 | 1/4 |
| 1498 | 439 | 6.475 | .040 | .275 ± .006 | 1.2595 | 6-1/2 | 7 | 1/4 |
| 1499 | 440 | 6.725 | .040 | .275 ± .006 | 1.3062 | 6-3/4 | 7-1/4 | 1/4 |
| 1500 | 441 | 6.975 | .040 | .275 ± .006 | 1.3528 | 7 | 7-1/2 | 1/4 |
| 1501 | 442 | 7.225 | .045 | .275 ± .006 | 1.3995 | 7-1/4 | 7-3/4 | 1/4 |
| 1502 | 443 | 7.475 | .045 | .275 ± .006 | 1.4461 | 7-1/2 | 8 | 1/4 |
| 1503 | 444 | 7.725 | .045 | .275 ± .006 | 1.4928 | 7-3/4 | 8-1/4 | 1/4 |
| 1504 | 445 | 7.975 | .045 | .275 ± .006 | 1.5394 | 8 | 8-1/2 | 1/4 |
| 1505 | 446 | 8.475 | .035 | .275 ± .006 | 1.6327 | 8-1/2 | 9 | 1/4 |
| 1506 | 447 | 8.975 | .055 | .275 ± .006 | 1.7260 | 9 | 9-1/2 | 1/4 |
| 1507 | 448 | 9.475 | .055 | .275 ± .006 | 1.8193 | 9-1/2 | 10 | 1/4 |
| 1508 | 449 | 9.975 | .055 | .275 ± .006 | 1.9126 | 10 | 10-1/2 | 1/4 |
| 1509 | 450 | 10.475 | .060 | .275 ± .006 | 2.0059 | 10-1/2 | 11 | 1/4 |
| 1510 | 451 | 10.975 | .060 | .275 ± .006 | 2.0092 | 11 | 11-1/2 | 1/4 |
| 1511 | 452 | 11.475 | .060 | .275 ± .006 | 2.1925 | 11-1/2 | 12 | 1/4 |
| 1512 | 453 | 11.975 | .060 | .275 ± .006 | 2.2858 | 12 | 12-1/2 | 1/4 |
| 1513 | 454 | 12.475 | .060 | .275 ± .006 | 2.3791 | 12-1/2 | 13 | 1/4 |
| 1514 | 455 | 12.975 | .060 | .275 ± .006 | 2.4724 | 13 | 13-1/2 | 1/4 |
| 1515 | 456 | 13.475 | .070 | .275 ± .006 | 2.5657 | 13-1/2 | 14 | 1/4 |
| 1516 | 457 | 13.975 | .070 | .275 ± .006 | 2.6590 | 14 | 14-1/2 | 1/4 |
| 1517 | 458 | 14.475 | .070 | .275 ± .006 | 2.7523 | 14-1/2 | 15 | 1/4 |
| 1518 | 459 | 14.975 | .070 | .275 ± .006 | 2.8456 | 15 | 15-1/2 | 1/4 |
| 1519 | 460 | 15.475 | .070 | .275 ± .006 | 2.9389 | 15-1/2 | 16 | 1/4 |
| 1520 | 461 | 15.955 | .075 | .275 ± .006 | 3.0285 | 16 | 16-1/2 | 1/4 |
| 1521 | 462 | 16.455 | .075 | .275 ± .006 | 3.1218 | 16-1/2 | 17 | 1/4 |
| 1522 | 463 | 16.955 | .080 | .275 ± .006 | 3.2151 | 17 | 17-1/2 | 1/4 |
| 1523 | 464 | 17.455 | .085 | .275 ± .006 | 3.3084 | 17-1/2 | 18 | 1/4 |
| 1524 | 465 | 17.955 | .085 | .275 ± .006 | 3.4017 | 18 | 18-1/2 | 1/4 |
| 1525 | 466 | 18.455 | .085 | .275 ± .006 | 3.4950 | 18-1/2 | 19 | 1/4 |
| 1526 | 467 | 18.955 | .090 | .275 ± .006 | 3.5883 | 19 | 19-1/2 | 1/4 |
| 1527 | 468 | 19.455 | .090 | .275 ± .006 | 3.6816 | 19-1/2 | 20 | 1/4 |
| 1528 | 469 | 19.955 | .095 | .275 ± .006 | 3.7749 | 20 | 20-1/2 | 1/4 |
| 1529 | 470 | 20.955 | .095 | .275 ± .006 | 3.9615 | 21 | 21-1/2 | 1/4 |
| 1530 | 471 | 21.955 | .100 | .275 ± .006 | 4.1481 | 22 | 22-1/2 | 1/4 |
| 1531 | 472 | 22.94 | .105 | .275 ± .006 | 4.3319 | 23 | 23-1/2 | 1/4 |
| 1532 | 473 | 23.94 | .110 | .275 ± .006 | 4.5185 | 24 | 24-1/2 | 1/4 |
| 1533 | 474 | 24.94 | .115 | .275 ± .006 | 4.7051 | 25 | 25-1/2 | 1/4 |
| 1534 | 475 | 25.94 | .120 | .275 ± .006 | 4.8917 | 26 | 26-1/2 | 1/4 |
MATERIALS
FEP PFA Encapsulated O-Ring
RT/Dygert Stock Material
Other Designations
Teflon® Encapsulated O-Ring
Composition
FEP and PFA Encapsulated O-Rings are solvent resistant and chemically inert
Temperature Range
-80 to 500 °F
Description
Teflon® Encapsulated O-Rings combine the resilience and sealing force of an elastomer with the chemical resistance of Teflon®. They consist of an elastomeric core of Silicone or Viton® with a relatively thin, molded encapsulation of Teflon® FEP or PFA polymer. This produces an elastomeric PTFE seal with maximum sealing capability. FEP Encapsulated O-Rings are solvent resistant and chemically inert (except for attack by alkaline metals, fluorine and some halogenated compounds at high temperatures) yet they have an elastomeric memory near that of rubber O-rings. FEP polymer also has an extremely low coefficient of friction (.1 to .2) and very low permeability to gases, making the Encapsulated O-Ring a virtually universal seal for use in hostile environments. PFA offers improved mechanical and creep properties at elevated temperatures (up to 500°F)
See the Silicone or Viton® materials section for their temperature and chemical resistance properties.
Information above applies to the generic material. Specific compounds may exhibit different properties.
Physical Properties*
| Excellent | Good | Fair | Poor | |
| Abrasion resistance | • | |||
| Elongation | • | |||
| Gas permeability | • | |||
| Radiation | • | |||
| Tear resistance | • | |||
| Tensile strength | • |
*Excellent, good, fair and poor are intended to serve as general guidelines only. Actual testing in the application environment is always recommended.
Information above applies to the generic material. Specific compounds may exhibit different properties.