Description An O-ring, also known as a packing, or a toric joint, is a mechanical gasket in the shape of a torus; it is a loop of elastomer with a round cross-section, designed to be seated in a groove and compressed during assembly between two or more parts, creating a seal at the interface.
O-Rings are the most common form of general purpose seal.
How does an O-Ring work? The compression (or more accurately the deformation) of the O-ring provides part of the sealing function. An additional sealing function is realized when the O-ring is activated by the pressure of the gas or liquid that the O-ring serves to contain. The containment surface ensures that the sealing function is maintained by keeping the O-ring where it needs to be. As pressure is applied to the seal the inherent flexibility of the material, and resistance to change of volume, transfer the pressure to the axis of compression.
Please download our O ring design guide for more detailed information.
Available Materials Nitriles (NBR, HNBR, XNBR) Fluoroelastomers (FKM, Viton®, TFE/P, Aflas®) Perfluoroelastomers (FFKM, Simriz®) Ethylene Propylene Diene Monomer (EPDM) Sizing information & Part Numbers For more detailed information regarding gland house recommendations and specification, please refer to our O-Ring design guide
SAE AS568 Sizing guide “0” Series Sizes AS 568 NOMINAL(REF.) MEASUREMENTS IN INCHES Size ID CS ID TOLERANCE ± CS ~001 1/32 1/32 0.029 0.004 0.040 ~002 3/64 3/64 0.042 0.004 0.050 ~003 1/16 1/16 0.056 0.004 0.060 ~004 5/64 1/16 0.070 0.005 0.070 ~005 3/32 1/16 0.101 0.005 0.070 ~006 1/8 1/16 0.114 0.005 0.070 ~007 5/32 1/16 0.145 0.005 0.070 ~008 3/16 1/16 0.176 0.005 0.070 ~009 7/32 1/16 0.208 0.005 0.070 ~010 1/4 1/16 0.239 0.005 0.070 ~011 5/16 1/16 0.301 0.005 0.070 ~012 3/8 1/16 0.364 0.005 0.070 ~013 7/16 1/16 0.426 0.005 0.070 ~014 1/2 1/16 0.489 0.005 0.070 ~015 9/16 1/16 0.551 0.007 0.070 ~016 5/8 1/16 0.614 0.009 0.070 ~017 11/16 1/16 0.676 0.009 0.070 ~018 3/4 1/16 0.739 0.009 0.070 ~019 13/16 1/16 0.801 0.009 0.070 ~020 7/8 1/16 0.864 0.009 0.070 ~021 15/16 1/16 0.926 0.009 0.070 ~022 1 1/16 0.989 0.010 0.070 ~023 1 1/16 1/16 1.051 0.010 0.070 ~024 1 1/8 1/16 1.114 0.010 0.070 ~025 1 3/16 1/16 1.176 0.011 0.070 ~026 1 1/4 1/16 1.239 0.011 0.070 ~027 1 5/16 1/16 1.301 0.011 0.070 ~028 1 3/8 1/16 1.364 0.013 0.070 ~029 1 1/2 1/16 1.489 0.013 0.070 ~030 1 5/8 1/16 1.614 0.013 0.070 ~031 1 3/4 1/16 1.739 0.015 0.070 ~032 1 7/8 1/16 1.864 0.015 0.070 ~033 2 1/16 1.989 0.018 0.070 ~034 2 1/8 1/16 2.114 0.018 0.070 ~035 2 1/4 1/16 2.239 0.018 0.070 ~036 2 3/8 1/16 2.364 0.018 0.070 ~037 2 1/2 1/16 2.489 0.018 0.070 ~038 2 5/8 1/16 2.614 0.020 0.070 ~039 2 3/4 1/16 2.739 0.020 0.070 ~040 2 7/8 1/16 2.864 0.020 0.070 ~041 3 1/16 2.989 0.024 0.070 ~042 3 1/4 1/16 3.239 0.024 0.070 ~043 3 1/2 1/16 3.489 0.024 0.070 ~044 3 3/4 1/16 3.739 0.027 0.070 ~045 4 1/16 3.989 0.027 0.070 ~046 4 1/4 1/16 4.239 0.030 0.070 ~047 4 1/2 1/16 4.489 0.030 0.070 ~048 4 3/4 1/16 4.739 0.030 0.070 ~049 5 1/16 4.989 0.037 0.070 ~050 5 1/4 1/16 5.239 0.037 0.070
“100” Series Sizes AS 568 NOMINAL(REF.) MEASUREMENTS IN INCHES Size ID CS ID TOLERANCE ± CS ~102 1/16 3/32 0.049 0.005 0.103 ~103 3/32 3/32 0.081 0.005 0.103 ~104 1/8 3/32 0.112 0.005 0.103 ~105 5/32 3/32 0.143 0.005 0.103 ~106 3/16 3/32 0.174 0.005 0.103 ~107 7/32 3/32 0.206 0.005 0.103 ~108 1/4 3/32 0.237 0.005 0.103 ~109 5/16 3/32 0.299 0.005 0.103 ~110 3/8 3/32 0.362 0.005 0.103 ~111 7/16 3/32 0.424 0.005 0.103 ~112 1/2 3/32 0.487 0.005 0.103 ~113 9/16 3/32 0.549 0.007 0.103 ~114 5/8 3/32 0.612 0.009 0.103 ~115 11/16 3/32 0.674 0.009 0.103 ~116 3/4 3/32 0.737 0.009 0.103 ~117 13/16 3/32 0.799 0.010 0.103 ~118 7/8 3/32 0.862 0.010 0.103 ~119 15/16 3/32 0.924 0.010 0.103 ~120 1 3/32 0.987 0.010 0.103 ~121 1 1/16 3/32 1.049 0.010 0.103 ~122 1 1/8 3/32 1.112 0.010 0.103 ~123 1 3/16 3/32 1.174 0.012 0.103 ~124 1 1/4 3/32 1.237 0.012 0.103 ~125 1 5/16 3/32 1.299 0.012 0.103 ~126 1 3/8 3/32 1.362 0.012 0.103 ~127 1 7/16 3/32 1.424 0.012 0.103 ~128 1 1/2 3/32 1.487 0.012 0.103 ~129 1 9/16 3/32 1.549 0.015 0.103 ~130 1 5/8 3/32 1.612 0.015 0.103 ~131 1 11/16 3/32 1.674 0.015 0.103 ~132 1 3/4 3/32 1.737 0.015 0.103 ~133 1 13/16 3/32 1.799 0.015 0.103 ~134 1 7/8 3/32 1.862 0.015 0.103 ~135 1 15/16 3/32 1.925 0.017 0.103 ~136 2 3/32 1.987 0.017 0.103 ~137 2 1/16 3/32 2.050 0.017 0.103 ~138 2 1/8 3/32 2.112 0.017 0.103 ~139 2 3/16 3/32 2.175 0.017 0.103 ~140 2 1/4 3/32 2.237 0.017 0.103 ~141 2 5/16 3/32 2.300 0.020 0.103 ~142 2 3/8 3/32 2.362 0.020 0.103 ~143 2 7/16 3/32 2.425 0.020 0.103 ~144 2 1/2 3/32 2.487 0.020 0.103 ~145 2 9/16 3/32 2.550 0.020 0.103 ~146 2 5/8 3/32 2.612 0.020 0.103 ~147 2 11/16 3/32 2.675 0.022 0.103 ~148 2 3/4 3/32 2.737 0.022 0.103 ~149 2 13/16 3/32 2.800 0.022 0.103 ~150 2 7/8 3/32 2.862 0.022 0.103 ~151 3 3/32 2.987 0.024 0.103 ~152 3 1/4 3/32 3.237 0.024 0.103 ~153 3 1/2 3/32 3.487 0.024 0.103 ~154 3 3/4 3/32 3.737 0.028 0.103 ~155 4 3/32 3.987 0.028 0.103 ~156 4 1/4 3/32 4.237 0.030 0.103 ~157 4 1/2 3/32 4.487 0.030 0.103 ~158 4 3/4 3/32 4.737 0.035 0.103 ~159 5 3/32 4.987 0.035 0.103 ~160 5 1/4 3/32 5.237 0.035 0.103 ~161 5 1/2 3/32 5.487 0.035 0.103 ~162 5 3/4 3/32 5.737 0.035 0.103 ~163 6 3/32 5.987 0.035 0.103 ~164 6 1/4 3/32 6.237 0.040 0.103 ~165 6 1/2 3/32 6.487 0.040 0.103 ~166 6 3/4 3/32 6.737 0.040 0.103 ~167 7 3/32 6.987 0.040 0.103 ~168 7 1/4 3/32 7.237 0.045 0.103 ~169 7 1/2 3/32 7.487 0.045 0.103 ~170 7 3/4 3/32 7.737 0.045 0.103 ~171 8 3/32 7.987 0.045 0.103 ~172 8 1/4 3/32 8.237 0.050 0.103 ~173 8 1/2 3/32 8.487 0.050 0.103 ~174 8 3/4 3/32 8.737 0.050 0.103 ~175 9 3/32 8.987 0.050 0.103 ~176 9 1/4 3/32 9.237 0.055 0.103 ~177 9 1/2 3/32 9.487 0.055 0.103 ~178 9 3/4 3/32 9.737 0.055 0.103
“200” Series Sizes AS 568 NOMINAL(REF.) MEASUREMENTS IN INCHES Size ID CS ID TOLERANCE ± CS ~201 3/16 1/8 0.171 0.005 0.139 ~202 1/4 1/8 0.234 0.005 0.139 ~203 5/16 1/8 0.296 0.005 0.139 ~204 3/8 1/8 0.359 0.005 0.139 ~205 7/16 1/8 0.421 0.005 0.139 ~206 1/2 1/8 0.484 0.005 0.139 ~207 9/16 1/8 0.546 0.007 0.139 ~208 5/8 1/8 0.609 0.009 0.139 ~209 11/16 1/8 0.671 0.009 0.139 ~210 3/4 1/8 0.734 0.010 0.139 ~211 13/16 1/8 0.796 0.010 0.139 ~212 7/8 1/8 0.859 0.010 0.139 ~213 15/16 1/8 0.921 0.010 0.139 ~214 1 1/8 0.984 0.010 0.139 ~215 1 1/16 1/8 1.046 0.010 0.139 ~216 1 1/8 1/8 1.109 0.012 0.139 ~217 1 3/16 1/8 1.171 0.012 0.139 ~218 1 1/4 1/8 1.234 0.012 0.139 ~219 1 5/16 1/8 1.296 0.012 0.139 ~220 1 3/8 1/8 1.359 0.012 0.139 ~221 1 7/16 1/8 1.421 0.012 0.139 ~222 1 1/2 1/8 1.484 0.015 0.139 ~223 1 5/8 1/8 1.609 0.015 0.139 ~224 1 3/4 1/8 1.734 0.015 0.139 ~225 1 7/8 1/8 1.859 0.018 0.139 ~226 2 1/8 1.984 0.018 0.139 ~227 2 1/8 1/8 2.109 0.018 0.139 ~228 2 1/4 1/8 2.234 0.020 0.139 ~229 2 3/8 1/8 2.359 0.020 0.139 ~230 2 1/2 1/8 2.484 0.020 0.139 ~231 2 5/8 1/8 2.609 0.020 0.139 ~232 2 3/4 1/8 2.734 0.024 0.139 ~233 2 7/8 1/8 2.859 0.024 0.139 ~234 3 1/8 2.984 0.024 0.139 ~235 3 1/8 1/8 3.109 0.024 0.139 ~236 3 1/4 1/8 3.234 0.024 0.139 ~237 3 3/8 1/8 3.359 0.024 0.139 ~238 3 1/2 1/8 3.484 0.024 0.139 ~239 3 5/8 1/8 3.609 0.028 0.139 ~240 3 3/4 1/8 3.734 0.028 0.139 ~241 3 7/8 1/8 3.859 0.028 0.139 ~242 4 1/8 3.984 0.028 0.139 ~243 4 1/8 1/8 4.109 0.028 0.139 ~244 4 1/4 1/8 4.234 0.030 0.139 ~245 4 3/8 1/8 4.359 0.030 0.139 ~246 4 1/2 1/8 4.484 0.030 0.139 ~247 4 5/8 1/8 4.609 0.030 0.139 ~248 4 3/4 1/8 4.734 0.030 0.139 ~249 4 7/8 1/8 4.859 0.035 0.139 ~250 5 1/8 4.984 0.035 0.139 ~251 5 1/8 1/8 5.109 0.035 0.139 ~252 5 1/4 1/8 5.234 0.035 0.139 ~253 5 3/8 1/8 5.359 0.035 0.139 ~254 5 1/2 1/8 5.484 0.035 0.139 ~255 5 5/8 1/8 5.609 0.035 0.139 ~256 5 3/4 1/8 5.734 0.035 0.139 ~257 5 7/8 1/8 5.859 0.035 0.139 ~258 6 1/8 5.984 0.035 0.139 ~259 6 1/4 1/8 6.234 0.040 0.139 ~260 6 1/2 1/8 6.484 0.040 0.139 ~261 6 3/4 1/8 6.734 0.040 0.139 ~262 7 1/8 6.984 0.040 0.139 ~263 7 1/4 1/8 7.234 0.045 0.139 ~264 7 1/2 1/8 7.484 0.045 0.139 ~265 7 3/4 1/8 7.734 0.045 0.139 ~266 8 1/8 7.984 0.045 0.139 ~267 8 1/4 1/8 8.234 0.050 0.139 ~268 8 1/2 1/8 8.484 0.050 0.139 ~269 8 3/4 1/8 8.734 0.050 0.139 ~270 9 1/8 8.984 0.050 0.139 ~271 9 1/4 1/8 9.234 0.055 0.139 ~272 9 1/2 1/8 9.484 0.055 0.139 ~273 9 3/4 1/8 9.734 0.055 0.139 ~274 10 1/8 9.984 0.055 0.139 ~275 10 1/2 1/8 10.484 0.055 0.139 ~276 11 1/8 10.984 0.065 0.139 ~277 11 1/2 1/8 11.484 0.065 0.139 ~278 12 1/8 11.984 0.065 0.139 ~279 13 1/8 12.984 0.065 0.139 ~280 14 1/8 13.984 0.065 0.139 ~281 15 1/8 14.984 0.065 0.139 ~282 16 1/8 15.955 0.075 0.139 ~283 17 1/8 16.955 0.080 0.139 ~284 18 1/8 17.955 0.085 0.139
“300” Series Sizes AS 568 NOMINAL(REF.) MEASUREMENTS IN INCHES Size ID CS ID TOLERANCE ± CS ~309 7/16 3/16 0.412 0.005 0.21 ~310 1/2 3/16 0.475 0.005 0.21 ~311 9/16 3/16 0.537 0.007 0.21 ~312 5/8 3/16 0.600 0.009 0.21 ~313 11/16 3/16 0.662 0.009 0.21 ~314 3/4 3/16 0.725 0.010 0.21 ~315 13/16 3/16 0.787 0.010 0.21 ~316 7/8 3/16 0.850 0.010 0.21 ~317 15/16 3/16 0.912 0.010 0.21 ~318 1 3/16 0.975 0.010 0.21 ~319 1 1/16 3/16 1.037 0.010 0.21 ~320 1 1/8 3/16 1.100 0.012 0.21 ~321 1 3/16 3/16 1.162 0.012 0.21 ~322 1 1/4 3/16 1.225 0.012 0.21 ~323 1 5/16 3/16 1.287 0.012 0.21 ~324 1 3/8 3/16 1.350 0.012 0.21 ~325 1 1/2 3/16 1.475 0.015 0.21 ~326 1 5/8 3/16 1.600 0.015 0.21 ~327 1 3/4 3/16 1.725 0.015 0.21 ~328 1 7/8 3/16 1.850 0.015 0.21 ~329 2 3/16 1.975 0.018 0.21 ~330 2 1/8 3/16 2.100 0.018 0.21 ~331 2 1/4 3/16 2.225 0.018 0.21 ~332 2 3/8 3/16 2.350 0.018 0.21 ~333 2 1/2 3/16 2.475 0.020 0.21 ~334 2 5/8 3/16 2.600 0.020 0.21 ~335 2 3/4 3/16 2.725 0.020 0.21 ~336 2 7/8 3/16 2.850 0.020 0.21 ~337 3 3/16 2.975 0.024 0.21 ~338 3 1/8 3/16 3.100 0.024 0.21 ~339 3 1/4 3/16 3.225 0.024 0.21 ~340 3 3/8 3/16 3.350 0.024 0.21 ~341 3 1/2 3/16 3.475 0.024 0.21 ~342 3 5/8 3/16 3.600 0.028 0.21 ~343 3 3/4 3/16 3.725 0.028 0.21 ~344 3 7/8 3/16 3.850 0.028 0.21 ~345 4 3/16 3.975 0.028 0.21 ~346 4 1/8 3/16 4.100 0.028 0.21 ~347 4 1/4 3/16 4.225 0.030 0.21 ~348 4 3/8 3/16 4.350 0.030 0.21 ~349 4 1/2 3/16 4.475 0.030 0.21 ~350 4 5/8 3/16 4.600 0.030 0.21 ~351 4 3/4 3/16 4.725 0.030 0.21 ~352 4 7/8 3/16 4.850 0.030 0.21 ~353 5 3/16 4.975 0.037 0.21 ~354 5 1/8 3/16 5.100 0.037 0.21 ~355 5 1/4 3/16 5.225 0.037 0.21 ~356 5 3/8 3/16 5.350 0.037 0.21 ~357 5 1/2 3/16 5.475 0.037 0.21 ~358 5 5/8 3/16 5.600 0.037 0.21 ~359 5 3/4 3/16 5.725 0.037 0.21 ~360 5 7/8 3/16 5.850 0.037 0.21 ~361 6 3/16 5.975 0.037 0.21 ~362 6 1/4 3/16 6.225 0.040 0.21 ~363 6 1/2 3/16 6.475 0.040 0.21 ~364 6 3/4 3/16 6.725 0.040 0.21 ~365 7 3/16 6.975 0.040 0.21 ~366 7 1/4 3/16 7.225 0.045 0.21 ~367 7 1/2 3/16 7.475 0.045 0.21 ~368 7 3/4 3/16 7.725 0.045 0.21 ~369 8 3/16 7.975 0.045 0.21 ~370 8 1/4 3/16 8.225 0.050 0.21 ~371 8 1/2 3/16 8.475 0.050 0.21 ~372 8 3/4 3/16 8.725 0.050 0.21 ~373 9 3/16 8.975 0.050 0.21 ~374 9 1/4 3/16 9.225 0.055 0.21 ~375 9 1/2 3/16 9.475 0.055 0.21 ~376 9 3/4 3/16 9.725 0.055 0.21 ~377 10 3/16 9.975 0.055 0.21 ~378 10 1/2 3/16 10.475 0.060 0.21 ~379 11 3/16 10.975 0.060 0.21 ~380 11 1/2 3/16 11.475 0.065 0.21 ~381 12 3/16 11.975 0.065 0.21 ~382 13 3/16 12.975 0.065 0.21 ~383 14 3/16 13.975 0.070 0.21 ~384 15 3/16 14.975 0.070 0.21 ~385 16 3/16 15.955 0.075 0.21 ~386 17 3/16 16.955 0.080 0.21 ~387 18 3/16 17.955 0.085 0.21 ~388 19 3/16 18.955 0.090 0.21 ~389 20 3/16 19.955 0.095 0.21 ~390 21 3/16 20.955 0.095 0.21 ~391 22 3/16 21.955 0.100 0.21 ~392 23 3/16 22.940 0.105 0.21 ~393 24 3/16 23.940 0.110 0.21 ~394 25 3/16 24.940 0.115 0.21 ~395 26 3/16 25.940 0.120 0.21
“400” Series Sizes AS 568 NOMINAL(REF.) MEASUREMENTS IN INCHES Size ID CS ID TOLERANCE ± CS ~425 4 1/2 1/4 4.475 0.033 0.275 ~426 4 5/8 1/4 4.600 0.033 0.275 ~427 4 3/4 1/4 4.725 0.033 0.275 ~428 4 7/8 1/4 4.850 0.033 0.275 ~429 5 1/4 4.975 0.037 0.275 ~430 5 1/8 1/4 5.100 0.037 0.275 ~431 5 1/4 1/4 5.225 0.037 0.275 ~432 5 3/8 1/4 5.350 0.037 0.275 ~433 5 1/2 1/4 5.475 0.037 0.275 ~434 5 5/8 1/4 5.600 0.037 0.275 ~435 5 3/4 1/4 5.725 0.037 0.275 ~436 5 7/8 1/4 5.850 0.037 0.275 ~437 6 1/4 5.975 0.037 0.275 ~438 6 1/4 1/4 6.225 0.040 0.275 ~439 6 1/2 1/4 6.475 0.040 0.275 ~440 6 3/4 1/4 6.725 0.040 0.275 ~441 7 1/4 6.975 0.040 0.275 ~442 7 1/4 1/4 7.225 0.045 0.275 ~443 7 1/2 1/4 7.475 0.045 0.275 ~444 7 3/4 1/4 7.725 0.045 0.275 ~445 8 1/4 7.975 0.045 0.275 ~446 8 1/2 1/4 8.475 0.055 0.275 ~447 9 1/4 8.975 0.055 0.275 ~448 9 1/2 1/4 9.475 0.055 0.275 ~449 10 1/4 9.975 0.055 0.275 ~450 10 1/2 1/4 10.475 0.060 0.275 ~451 11 1/4 10.975 0.060 0.275 ~452 11 1/2 1/4 11.475 0.060 0.275 ~453 12 1/4 11.975 0.060 0.275 ~454 12 1/2 1/4 12.475 0.060 0.275 ~455 13 1/4 12.975 0.060 0.275 ~456 13 1/2 1/4 13.475 0.070 0.275 ~457 14 1/4 13.975 0.070 0.275 ~458 14 1/2 1/4 14.475 0.070 0.275 ~459 15 1/4 14.975 0.070 0.275 ~460 15 1/2 1/4 15.475 0.070 0.275 ~461 16 1/4 15.955 0.075 0.275 ~462 16 1/2 1/4 16.455 0.075 0.275 ~463 17 1/4 16.955 0.080 0.275 ~464 17 1/2 1/4 17.455 0.085 0.275 ~465 18 1/4 17.955 0.085 0.275 ~466 18 1/2 1/4 18.455 0.085 0.275 ~467 19 1/4 18.955 0.090 0.275 ~468 19 1/2 1/4 19.455 0.090 0.275 ~469 20 1/4 19.955 0.095 0.275 ~470 21 1/4 20.955 0.095 0.275 ~471 22 1/4 21.955 0.100 0.275 ~472 23 1/4 22.940 0.105 0.275 ~473 24 1/4 23.940 0.110 0.275 ~474 25 1/4 24.940 0.115 0.275 ~475 26 1/4 25.940 0.120 0.275
“900” Series Sizes AS 568 NOMINAL(REF.) MEASUREMENTS IN INCHES Size ID CS ID TOLERANCE ± CS ~901 3/32 0.185 0.005 0.056 ~902 1/8 0.239 0.005 0.064 ~903 3/16 0.301 0.005 0.064 ~904 1/4 0.351 0.005 0.072 ~905 5/16 0.414 0.005 0.072 ~906 3/8 0.468 0.005 0.078 ~907 7/16 0.530 0.007 0.082 ~908 1/2 0.644 0.009 0.087 ~909 9/16 0.706 0.009 0.097 ~910 5/8 0.755 0.009 0.097 ~911 11/16 0.863 0.009 0.116 ~912 3/4 0.924 0.009 0.116 ~913 13/16 0.986 0.010 0.116 ~914 7/8 1.047 0.010 0.116 ~916 1 1.171 0.010 0.116 ~918 1 1/8 1.355 0.012 0.116 ~920 1 1/4 1.475 0.014 0.118 ~924 1 1/2 1.720 0.014 0.118 ~928 1 3/4 2.090 0.018 0.118 ~932 2 2.337 0.018 0.118