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AS568 O-Ring Size Chart

All 361 standard sizes, in millimetres and inches. Grouped by series, because every ring in a series shares one cross section.

If you have a ring in your hand and need the dash number, the finder is faster than scanning this — type two measurements and it ranks the candidates for you.

000 series — 1/16" cross section

Pneumatics, instrumentation, small static seals.

DashID (mm)CS (mm)OD (mm)ID (in)CS (in)OD (in)
-0010.741.022.770.0290.040.109
-0021.071.273.610.0420.050.142
-0031.421.524.470.0560.060.176
-0041.781.785.330.070.070.21
-0052.571.786.120.1010.070.241
-0062.91.786.450.1140.070.254
-0073.681.787.240.1450.070.285
-0084.471.788.030.1760.070.316
-0095.281.788.840.2080.070.348
-0106.071.789.630.2390.070.379
-0117.651.7811.20.3010.070.441
-0129.251.7812.80.3640.070.504
-01310.821.7814.380.4260.070.566
-01412.421.7815.980.4890.070.629
-01514.01.7817.550.5510.070.691
-01615.61.7819.150.6140.070.754
-01717.171.7820.730.6760.070.816
-01818.771.7822.330.7390.070.879
-01920.351.7823.90.8010.070.941
-02021.951.7825.50.8640.071.004
-02123.521.7827.080.9260.071.066
-02225.121.7828.680.9890.071.129
-02326.71.7830.251.0510.071.191
-02428.31.7831.851.1140.071.254
-02529.871.7833.431.1760.071.316
-02631.471.7835.031.2390.071.379
-02733.051.7836.61.3010.071.441
-02834.651.7838.21.3640.071.504
-02937.821.7841.381.4890.071.629
-03041.01.7844.551.6140.071.754
-03144.171.7847.731.7390.071.879
-03247.351.7850.91.8640.072.004
-03350.521.7854.081.9890.072.129
-03453.71.7857.252.1140.072.254
-03556.871.7860.432.2390.072.379
-03660.051.7863.62.3640.072.504
-03763.221.7866.782.4890.072.629
-03866.41.7869.952.6140.072.754
-03969.571.7873.132.7390.072.879
-04072.751.7876.32.8640.073.004
-04175.921.7879.482.9890.073.129
-04282.271.7885.833.2390.073.379
-04388.621.7892.183.4890.073.629
-04494.971.7898.533.7390.073.879
-045101.321.78104.883.9890.074.129
-046107.671.78111.234.2390.074.379
-047114.021.78117.584.4890.074.629
-048120.371.78123.934.7390.074.879
-049126.721.78130.284.9890.075.129
-050133.071.78136.635.2390.075.379

100 series — 3/32" cross section

Hydraulics, pumps, valves.

DashID (mm)CS (mm)OD (mm)ID (in)CS (in)OD (in)
-1021.242.626.480.0490.1030.255
-1032.062.627.290.0810.1030.287
-1042.842.628.080.1120.1030.318
-1053.632.628.860.1430.1030.349
-1064.422.629.650.1740.1030.38
-1075.212.6210.440.2050.1030.411
-1086.022.6211.250.2370.1030.443
-1097.592.6212.830.2990.1030.505
-1109.192.6214.430.3620.1030.568
-11110.772.6216.00.4240.1030.63
-11212.372.6217.60.4870.1030.693
-11313.942.6219.180.5490.1030.755
-11415.542.6220.780.6120.1030.818
-11517.122.6222.350.6740.1030.88
-11618.722.6223.950.7370.1030.943
-11720.292.6225.530.7990.1031.005
-11821.892.6227.130.8620.1031.068
-11923.472.6228.70.9240.1031.13
-12025.072.6230.30.9870.1031.193
-12126.642.6231.881.0490.1031.255
-12228.242.6233.481.1120.1031.318
-12329.822.6235.051.1740.1031.38
-12431.422.6236.651.2370.1031.443
-12532.992.6238.231.2990.1031.505
-12634.592.6239.831.3620.1031.568
-12736.172.6241.41.4240.1031.63
-12837.772.6243.01.4870.1031.693
-12939.342.6244.581.5490.1031.755
-13040.942.6246.181.6120.1031.818
-13142.522.6247.751.6740.1031.88
-13244.122.6249.351.7370.1031.943
-13345.692.6250.931.7990.1032.005
-13447.292.6252.531.8620.1032.068
-13548.892.6254.131.9250.1032.131
-13650.472.6255.71.9870.1032.193
-13752.072.6257.32.050.1032.256
-13853.642.6258.882.1120.1032.318
-13955.242.6260.482.1750.1032.381
-14056.822.6262.052.2370.1032.443
-14158.422.6263.652.30.1032.506
-14259.992.6265.232.3620.1032.568
-14361.592.6266.832.4250.1032.631
-14463.172.6268.42.4870.1032.693
-14564.772.6270.02.550.1032.756
-14666.342.6271.582.6120.1032.818
-14767.942.6273.182.6750.1032.881
-14869.522.6274.752.7370.1032.943
-14971.122.6276.352.80.1033.006
-15072.692.6277.932.8620.1033.068
-15175.872.6281.12.9870.1033.193
-15282.222.6287.453.2370.1033.443
-15388.572.6293.83.4870.1033.693
-15494.922.62100.153.7370.1033.943
-155101.272.62106.53.9870.1034.193
-156107.622.62112.854.2370.1034.443
-157113.972.62119.24.4870.1034.693
-158120.322.62125.554.7370.1034.943
-159126.672.62131.94.9870.1035.193
-160133.022.62138.255.2370.1035.443
-161139.372.62144.65.4870.1035.693
-162145.722.62150.955.7370.1035.943
-163152.072.62157.35.9870.1036.193
-164158.422.62163.656.2370.1036.443
-165164.772.62170.06.4870.1036.693
-166171.122.62176.356.7370.1036.943
-167177.472.62182.76.9870.1037.193
-168183.822.62189.057.2370.1037.443
-169190.172.62195.47.4870.1037.693
-170196.522.62201.757.7370.1037.943
-171202.872.62208.17.9870.1038.193
-172209.222.62214.458.2370.1038.443
-173215.572.62220.88.4870.1038.693
-174221.922.62227.158.7370.1038.943
-175228.272.62233.58.9870.1039.193
-176234.622.62239.859.2370.1039.443
-177240.972.62246.29.4870.1039.693
-178247.322.62252.559.7370.1039.943

200 series — 1/8" cross section

General purpose, cylinders.

DashID (mm)CS (mm)OD (mm)ID (in)CS (in)OD (in)
-2014.343.5311.40.1710.1390.449
-2025.943.5313.00.2340.1390.512
-2037.523.5314.580.2960.1390.574
-2049.123.5316.180.3590.1390.637
-20510.693.5317.750.4210.1390.699
-20612.293.5319.350.4840.1390.762
-20713.873.5320.930.5460.1390.824
-20815.473.5322.530.6090.1390.887
-20917.043.5324.10.6710.1390.949
-21018.643.5325.70.7340.1391.012
-21120.223.5327.280.7960.1391.074
-21221.823.5328.880.8590.1391.137
-21323.393.5330.450.9210.1391.199
-21424.993.5332.050.9840.1391.262
-21526.573.5333.631.0460.1391.324
-21628.173.5335.231.1090.1391.387
-21729.743.5336.81.1710.1391.449
-21831.343.5338.41.2340.1391.512
-21932.923.5339.981.2960.1391.574
-22034.523.5341.581.3590.1391.637
-22136.093.5343.151.4210.1391.699
-22237.693.5344.751.4840.1391.762
-22340.873.5347.931.6090.1391.887
-22444.043.5351.11.7340.1392.012
-22547.223.5354.281.8590.1392.137
-22650.393.5357.451.9840.1392.262
-22753.573.5360.632.1090.1392.387
-22856.743.5363.82.2340.1392.512
-22959.923.5366.982.3590.1392.637
-23063.093.5370.152.4840.1392.762
-23166.273.5373.332.6090.1392.887
-23269.443.5376.52.7340.1393.012
-23372.623.5379.682.8590.1393.137
-23475.793.5382.852.9840.1393.262
-23578.973.5386.033.1090.1393.387
-23682.143.5389.23.2340.1393.512
-23785.323.5392.383.3590.1393.637
-23888.493.5395.553.4840.1393.762
-23991.673.5398.733.6090.1393.887
-24094.843.53101.93.7340.1394.012
-24198.023.53105.083.8590.1394.137
-242101.193.53108.253.9840.1394.262
-243104.373.53111.434.1090.1394.387
-244107.543.53114.64.2340.1394.512
-245110.723.53117.784.3590.1394.637
-246113.893.53120.954.4840.1394.762
-247117.073.53124.134.6090.1394.887
-248120.243.53127.34.7340.1395.012
-249123.423.53130.484.8590.1395.137
-250126.593.53133.654.9840.1395.262
-251129.773.53136.835.1090.1395.387
-252132.943.53140.05.2340.1395.512
-253136.123.53143.185.3590.1395.637
-254139.293.53146.355.4840.1395.762
-255142.473.53149.535.6090.1395.887
-256145.643.53152.75.7340.1396.012
-257148.823.53155.885.8590.1396.137
-258151.993.53159.055.9840.1396.262
-259158.343.53165.46.2340.1396.512
-260164.693.53171.756.4840.1396.762
-261171.043.53178.16.7340.1397.012
-262177.393.53184.456.9840.1397.262
-263183.743.53190.87.2340.1397.512
-264190.093.53197.157.4840.1397.762
-265196.443.53203.57.7340.1398.012
-266202.793.53209.857.9840.1398.262
-267209.143.53216.28.2340.1398.512
-268215.493.53222.558.4840.1398.762
-269221.843.53228.98.7340.1399.012
-270228.193.53235.258.9840.1399.262
-271234.543.53241.69.2340.1399.512
-272240.893.53247.959.4840.1399.762
-273247.243.53254.39.7340.13910.012
-274253.593.53260.659.9840.13910.262
-275266.293.53273.3510.4840.13910.762
-276278.993.53286.0510.9840.13911.262
-277291.693.53298.7511.4840.13911.762
-278304.393.53311.4511.9840.13912.262
-279329.793.53336.8512.9840.13913.262
-280355.193.53362.2513.9840.13914.262
-281380.593.53387.6514.9840.13915.262
-282405.993.53413.0515.9840.13916.262
-283431.393.53438.4516.9840.13917.262
-284456.793.53463.8517.9840.13918.262

300 series — 3/16" cross section

Heavy hydraulics, higher pressure.

DashID (mm)CS (mm)OD (mm)ID (in)CS (in)OD (in)
-30910.465.3321.130.4120.210.832
-31012.065.3322.730.4750.210.895
-31113.645.3324.310.5370.210.957
-31215.245.3325.910.60.211.02
-31316.815.3327.480.6620.211.082
-31418.415.3329.080.7250.211.145
-31519.995.3330.660.7870.211.207
-31621.595.3332.260.850.211.27
-31723.165.3333.830.9120.211.332
-31824.765.3335.430.9750.211.395
-31926.345.3337.011.0370.211.457
-32027.945.3338.611.10.211.52
-32129.515.3340.181.1620.211.582
-32231.125.3341.781.2250.211.645
-32332.695.3343.361.2870.211.707
-32434.295.3344.961.350.211.77
-32537.475.3348.131.4750.211.895
-32640.645.3351.311.60.212.02
-32743.815.3354.481.7250.212.145
-32846.995.3357.661.850.212.27
-32950.165.3360.831.9750.212.395
-33053.345.3364.012.10.212.52
-33156.525.3367.182.2250.212.645
-33259.695.3370.362.350.212.77
-33362.875.3373.532.4750.212.895
-33466.045.3376.712.60.213.02
-33569.225.3379.882.7250.213.145
-33672.395.3383.062.850.213.27
-33775.565.3386.232.9750.213.395
-33878.745.3389.413.10.213.52
-33981.915.3392.583.2250.213.645
-34085.095.3395.763.350.213.77
-34188.275.3398.933.4750.213.895
-34291.445.33102.113.60.214.02
-34394.615.33105.283.7250.214.145
-34497.795.33108.463.850.214.27
-345100.975.33111.633.9750.214.395
-346104.145.33114.814.10.214.52
-347107.315.33117.984.2250.214.645
-348110.495.33121.164.350.214.77
-349113.665.33124.334.4750.214.895
-350116.845.33127.514.60.215.02
-351120.015.33130.684.7250.215.145
-352123.195.33133.864.850.215.27
-353126.365.33137.034.9750.215.395
-354129.545.33140.215.10.215.52
-355132.715.33143.385.2250.215.645
-356135.895.33146.565.350.215.77
-357139.065.33149.735.4750.215.895
-358142.245.33152.915.60.216.02
-359145.415.33156.085.7250.216.145
-360148.595.33159.265.850.216.27
-361151.765.33162.435.9750.216.395
-362158.115.33168.786.2250.216.645
-363164.465.33175.136.4750.216.895
-364170.815.33181.486.7250.217.145
-365177.165.33187.836.9750.217.395
-366183.515.33194.187.2250.217.645
-367189.865.33200.537.4750.217.895
-368196.215.33206.887.7250.218.145
-369202.565.33213.237.9750.218.395
-370208.915.33219.588.2250.218.645
-371215.265.33225.938.4750.218.895
-372221.615.33232.288.7250.219.145
-373227.965.33238.638.9750.219.395
-374234.315.33244.989.2250.219.645
-375240.665.33251.339.4750.219.895
-376247.015.33257.689.7250.2110.145
-377253.365.33264.039.9750.2110.395
-378266.065.33276.7310.4750.2110.895
-379278.765.33289.4310.9750.2111.395
-380291.465.33302.1311.4750.2111.895
-381304.165.33314.8311.9750.2112.395
-382329.565.33340.2312.9750.2113.395
-383354.965.33365.6313.9750.2114.395
-384380.365.33391.0314.9750.2115.395
-385405.765.33416.4315.9750.2116.395
-386431.175.33441.8316.9750.2117.395
-387456.565.33467.2317.9750.2118.395

400 series — 1/4" cross section

Industrial flanges and piping.

DashID (mm)CS (mm)OD (mm)ID (in)CS (in)OD (in)
-425113.666.99127.634.4750.2755.025
-426116.846.99130.814.60.2755.15
-427120.016.99133.984.7250.2755.275
-428123.196.99137.164.850.2755.4
-429126.366.99140.334.9750.2755.525
-430129.546.99143.515.10.2755.65
-431132.716.99146.685.2250.2755.775
-432135.896.99149.865.350.2755.9
-433139.066.99153.035.4750.2756.025
-434142.246.99156.215.60.2756.15
-435145.416.99159.385.7250.2756.275
-436148.596.99162.565.850.2756.4
-437151.766.99165.735.9750.2756.525
-438158.116.99172.086.2250.2756.775
-439164.466.99178.436.4750.2757.025
-440170.816.99184.786.7250.2757.275
-441177.166.99191.136.9750.2757.525
-442183.516.99197.487.2250.2757.775
-443189.866.99203.847.4750.2758.025
-444196.216.99210.197.7250.2758.275
-445202.566.99216.537.9750.2758.525
-446208.916.99222.888.2250.2758.775
-447215.266.99229.238.4750.2759.025
-448221.616.99235.598.7250.2759.275
-449227.966.99241.948.9750.2759.525
-450234.316.99248.289.2250.2759.775
-451240.666.99254.639.4750.27510.025
-452247.016.99260.999.7250.27510.275
-453253.366.99267.339.9750.27510.525
-454266.066.99280.0310.4750.27511.025
-455278.766.99292.7410.9750.27511.525
-456291.466.99305.4411.4750.27512.025
-457304.166.99318.1311.9750.27512.525
-458316.866.99330.8312.4750.27513.025
-459329.566.99343.5312.9750.27513.525
-460342.266.99356.2413.4750.27514.025
-461354.966.99368.9413.9750.27514.525
-462367.666.99381.6314.4750.27515.025
-463380.366.99394.3314.9750.27515.525
-464393.066.99407.0315.4750.27516.025
-465405.766.99419.7315.9750.27516.525
-466418.476.99432.4416.4750.27517.025
-467431.176.99445.1416.9750.27517.525
-468443.876.99457.8417.4750.27518.025
-469456.566.99470.5417.9750.27518.525
-470469.266.99483.2418.4750.27519.025
-471481.976.99495.9418.9750.27519.525
-472494.676.99508.6419.4750.27520.025
-473507.376.99521.3419.9750.27520.525
-474520.076.99534.0320.4750.27521.025
-475532.766.99546.7420.9750.27521.525

900 series — mixed cross section

SAE straight-thread boss gaskets.

DashID (mm)CS (mm)OD (mm)ID (in)CS (in)OD (in)
-9014.71.427.540.1850.0560.297
-9026.071.639.320.2390.0640.367
-9037.651.6310.90.3010.0640.429
-9048.921.8312.570.3510.0720.495
-90510.521.8314.170.4140.0720.558
-90611.891.9815.850.4680.0780.624
-90713.462.0817.630.530.0820.694
-90816.362.2120.780.6440.0870.818
-90917.932.4622.860.7060.0970.9
-91019.182.4624.10.7550.0970.949
-91121.922.9527.810.8630.1161.095
-91223.472.9529.360.9240.1161.156
-91325.042.9530.940.9860.1161.218
-91426.592.9532.491.0470.1161.279
-91629.742.9535.641.1710.1161.403
-91834.422.9540.311.3550.1161.587
-92037.473.043.461.4750.1181.711
-92443.693.049.681.720.1181.956
-92853.093.059.082.090.1182.326
-93259.363.065.352.3370.1182.573
Millimetre figures are computed from the inch dimensions rather than copied. Published charts commonly disagree with their own inch columns on the largest sizes — several list dash 282 as 405.26 mm when 15.984″ converts to 405.99 mm. Deriving from one column removes that class of error.