BS4518 SIZE CHART
CHEMICAL COMPATIBILITY CHART
JIS B 2401 SIZE CHART

BS1806 - AS568A O-ring Sizes

3/32" - 2.62MM C/S
1/8" - 3.53MM C/S
Imperial O‑Ring Sizes & Tolerances (BS1806 & AS568A)
1/16" cross section
1.78mm ± 0.08mm 0.070"± 0.003"
Internal diameter Nominal size
Part No. (BS) mm Tol ± Inch Tol ± Shaft Bore
•001 0.74 0.13 0.029 0.005 1/32 -
•002 1.07 0.13 0.042 0.005 3/64 -
•003 1.42 0.13 0.056 0.005 1/16 -
•606 1.78 0.13 0.070 0.005 5/64 -
004 1.78 0.13 0.070 0.005 5/64 13/64
•607 2.54 0.13 0.100 0.005 - -
005 2.54 0.13 0.100 0.005 7/64 15/65
006 2.90 0.13 .114 0.005 - -
801 3.14 0.13 0.124 0.005 5/32 9/32
007 3.68 0.13 0.145 0.005 3/16 5/16
008 4.48 0.13 0.176 0.005 7/32 11/32
802 4.76 0.13 0.187 0.005 - -
009 5.28 0.13 0.208 0.005 7/32 11/32
010 6.07 0.13 0.239 0.005 1/4 3/8
803 6.35 0.13 0.250 0.005 - -
610 6.75 0.13 0.266 0.005 17/64 -
011 7.66 0.13 0.302 0.005 5/16 7/1
611 8.73 0.13 0.344 0.005 11/3 15/3
012 9.25 0.13 0.364 0.005 3/8 1/2
013 10.82 0.13 0.426 0.005 7/16 9/16
806 11.11 0.13 0.437 0.005 7/16 -
014 12.42 0.13 0.489 0.005 1/2 5/8
015 14.00 0.13 0.551 0.005 9/16 11/16
016 15.60 0.13 0.614 0.005 5/8 3/4
017 17.16 0.13 .676 0.005 11/16 13/16
018 18.77 0.13 0.739 0.005 3/4 7/8
019 20.35 0.15 0.801 0.006 13/16 15/16
020 21.95 0.15 0.864 0.006 7/8 1
021 23.53 0.15 0.926 0.006 15/16 1.1/16
022 25.12 0.15 0.989 0.006 1 1.1/8
023 26.70 0.15 1.051 0.006 1.1/16 1.3/16
024 28.30 0.15 1.114 0.006 1.1/8 1.1/4
025 29.87 0.15 1.176 0.006 1.3/16 1.5/16
026 31.47 0.15 1.239 0.006 1.1/4 1.3/8
027 33.05 0.15 1.301 0.006 1.5/16 1.7/16
028 34.65 0.15 1.364 0.006 1.3/8 1.1/2
517 36.27 0.38 1.428 0.015 1.7/16 1.9/16
029 37.82 0.25 1.489 0.010 1.1/2 1.5/8
3/16" - 5.34MM C/S
1/4 - 6.99MM C/S
Imperial O‑Ring Sizes & Tolerances (BS1806 & AS568A)
1/16" cross section
1.78mm ± 0.08mm 0.070"± 0.003"
Internal diameter Nominal size
Part No. (BS) mm Tol ± Inch Tol ± Shaft Bore
519 39.45 0.38 1.553 0.015 1.9/16 1.11/16
030 41.00 0.25 1.614 0.010 1.5/8 1.3/4
031 44.17 0.25 1.739 0.010 1.3/4 1.7/8
032 47.37 0.25 1.865 0.010 1.7/8 2
033 50.52 0.25 1.989 0.010 2 2.1/8
034 53.67 0.25 2.113 0.010 2.1/8 2.1/4
035 56.87 0.25 2.239 0.010 2.1/4 2.3/8
036 60.04 0.25 2.364 0.010 2.3/8 2.1/2
037 63.22 0.25 2.489 0.010 2.1/2 2.5/8
038 66.40 0.25 2.614 0.010 2.5/8 2.3/4
039 69.57 0.25 2.739 0.010 2.3/4 2.7/8
040 72.76 0.38 2.865 0.015 2.7/8 3
041 75.92 0.38 2.989 0.015 3 3.1/8
532 79.00 0.51 3.110 0.020 3.1/8 3.1/4
042 82.8 0.38 3.239 0.015 3.1/4 3.3/8
534 85.34 0.51 3.360 0.020 3.3/8 3.1/2
043 88.62 0.38 3.489 0.015 3.1/2 3.5/8
536 91.70 0.51 3.610 0.020 3.5/8 3.3/4
044 94.97 0.38 3.739 0.015 3.3/4 3.7/8
538 98.05 0.51 3.860 0.020 3.7/8 4
540 104.40 0.51 4.110 0.020 4.1/8 4.1/4
046 107.70 0.38 4.240 0.015 4.1/4 4.3/8
542 110.74 0.51 4.360 0.020 4.3/8 4.1/2
047 114.00 0.38 4.488 0.015 4.1/2 4.5/8
544 117.10 0.51 4.610 0.020 4.5/8 4.3/4
048 120.40 0.38 4.740 0.015 4.3/4 4.7/8
546 123.44 0.51 4.860 0.020 4.7/8 5
049 126.76 0.38 4.991 0.015 5 5.1/8
548 129.40 0.71 5.094 0.028 5.1/8 5.1/4
050 133.07 0.38 5.239 0.015 5.1/4 5.3/8
Imperial O‑Ring Sizes & Tolerances
• Note: Cross Section Diameter
O-Ring Size (Metric) O-Ring Size (Imperial)
001 = 1.02 ± 0.07 0.040" ± 0.003"
002 = 1.27 ± 0.07 0.050" ± 0.003"
003 = 1.52 ± 0.07 0.060" ± 0.003"
606 = 1.02 ± 0.07 0.040" ± 0.003"
607 = 1.02 ± 0.07 0.040" ± 0.003"