O-Ring Sizes

O-Ring sizes and dimensions BS1806 - AS568A
Materials
NBR FKM/VIT EPDM
HNBR FFKM Neoprene
PTFE Silicone Fluorosilicone

Other materials are available on request

1/4" cross section
6.99mm ± 0.15mm 0.275"± 0.006"
Internal diameter Nominal size
Part No. (BS) mm Tol ± Inch Tol ± Shaft Bore
425 113.67 0.38 4.475 0.015 4.1/2 5
624 114.70 0.38 4.516 0.015 4.9/16 5.1/16
426 116.84 0.38 4.600 0.015 4.5/8 5.1/8
427 120.02 0.38 4.725 0.015 4.3/4 5.1/4
428 123.20 0.38 4.850 0.015 4.7/8 5.3/8
625 124.60 0.38 4.906 0.015 - -
429 126.37 0.38 4.975 0.015 5 5.1/2
430 129.54 0.58 5.100 0.023 5.1/8 5.5/8
431 132.72 0.58 5.225 0.023 5.1/4 5.3/4
626 134.50 0.58 5.297 0.023 - -
432 135.90 0.58 5.350 0.023 5.3/8 5.7/8
433 139.07 0.58 5.475 0.023 5.1/2 6
434 142.24 0.58 5.600 0.023 5.5/8 6.1/8
435 145.42 0.58 5.725 0.023 5.3/4 6.1/4
436 148.60 0.58 5.850 0.023 5.7/8 6.3/8
437 151.77 0.58 5.975 0.023 6 6.1/2
872 155.60 0.58 6.126 0.023 6.1/8 6.5/8
438 158.12 0.58 6.225 0.023 6.1/4 6.3/4
627 159.50 0.58 6.281 0.023 - -
874 161.90 0.58 6.375 0.023 - -
439 164.47 0.58 6.475 0.023 6.1/2 7
628 166.70 0.58 6.563 0.023 6.9/16 7.1/16
876 168.30 0.58 6.625 0.023 6.5/8 7.1/8
440 170.82 0.58 6.725 0.023 6.3/4 7.1/4
878 174.60 0.58 6.875 0.023 - -
441 177.17 0.58 6.975 0.023 7 7.1/2
441A 181.00 0.76 7.125 0.030 - -
442 183.52 0.76 7.225 0.030 7.1/4 7.3/4
442A 187.30 0.76 7.375 0.030 7.3/8 7.7/8
443 189.87 0.76 7.475 0.030 7.1/2 8
443A 193.70 0.76 7.625 0.030 7.5/8 8.1/8
444 196.22 0.76 7.725 0.030 7.3/4 8.1/4
444A 199.80 0.76 7.875 0.030 7.7/8 8.3/8
445 202.57 0.76 7.975 0.030 8 8.1/2
445A 208.92 0.76 8.225 0.030 8.1/4 8.3/4
446 215.27 0.76 8.475 0.030 8.1/2 9
446A 221.62 0.76 8.725 0.030 8.3/4 9.1/4
1/4" cross section
6.99mm ± 0.15mm 0.275"± 0.006"
Internal diameter Nominal size
Part No. (BS) mm Tol ± Inch Tol ± Shaft Bore
447 227.97 0.76 8.975 0.030 9 9.1/2
447A 234.32 0.76 9.225 0.030 9.1/4 9.3/4
448 240.67 0.76 9.475 0.030 9.1/2 10
448A 247.00 0.76 9.725 0.030 9.3/4 10.1/4
449 253.57 0.76 9.975 0.030 10 10.1/2
449A 259.70 0.76 10.225 0.030 10.1/4 10.3/4
450 266.07 0.76 10.475 0.030 10.1/2 11
450A 272.40 0.76 10.725 0.030 10.3/4 11.1/4
451 278.77 0.76 10.975 0.030 11 11.1/2
451A 285.10 0.76 11.225 0.030 11.1/4 11.3/4
452 291.47 0.76 11.475 0.030 11.1/2 12
452A 297.80 0.76 11.725 0.030 11.3/4 12.1/4
453 304.17 0.76 11.975 0.030 12 12.1/2
453A 310.50 0.76 12.225 0.030 12.1/4 12.3/4
454 316.87 0.76 12.475 0.030 12.1/2 13
455 329.57 0.76 12.975 0.030 13 13.1/2
456 342.27 0.76 13.475 0.030 13.1/2 14
457 354.97 0.76 13.975 0.030 14 14.1/2
458 367.67 0.76 14.475 0.030 14.1/2 15
459 380.37 0.76 14.975 0.030 15 15.1/2
460 393.07 0.76 15.475 0.030 15.1/2 16
461 405.26 1.14 15.955 0.045 1 16.1/2
462 417.96 1.14 16.455 0.045 16.1/2 17
463 430.66 1.14 16.955 0.045 17 17.1/2
464 430.66 1.14 17.455 0.045 17.1/2 18
465 456.06 1.14 17.955 0.045 1 18.1/2
466 468.76 1.14 18.455 0.045 18.1/2 19
467 481.46 1.14 18.955 0.045 19 19.1/2
468 494.16 1.14 19.455 0.045 19.1/2 20
469 506.86 1.14 19.955 0.045 20 20.1/2
470 532.26 1.14 20.995 0.045 21 21.1/2
471 557.66 1.14 21.955 0.045 22 22.1/2
472 582.68 1.52 22.840 0.060 23 23.1/2
473 608.08 1.52 23.940 0.060 24 24.1/2
474 633.48 1.52 24.940 0.060 25 25.1/2
475 658.88 1.52 25.940 0.060 26 26.1/2