Overview of 900 Series Boss O-Rings & SAE Flange O-Rings

Boss o-rings are used in sealing straight thread tube fittings (Boss Type) in the design and service of hydraulic equipment. Boss o-rings can be used in conjunction with a nut to work as a seal and act as a cushion between the two mating metal surfaces.

Boss o-ring sizes fall under the AS568 900 Series classification. Nitrile 90 Durometer o-rings are typically used, however, a multitude of o-ring compounds come in Boss sizes.

Flange o-rings seal and contain pressurized fluid in flange connections such as pipes, pumps, and valves. Flange o-rings are placed in a groove between two flat metal surfaces, which are bolted together to form a sealed connection.

Flange o-ring sizes are contained within the AS568 200 Series classification. Nitrile 90 Durometer o-rings are most commonly utilized, but multiple o-ring compounds are available in Flange sizes.

If you require more information on Boss o-rings or Flange o-rings, please give us a call at 832-448-5550 or fill out the Product Inquiry Form to receive a quote or more information.

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Boss O-Ring Size Chart

Boss o-ring sizes and corresponding dimensions are shown in the interactive table below. Dash Numbers in the left column link to their specific size filtering in our online store.

Dash # Tube OD CS Inch ID Inch Tol Inch CS mm ID mm Tol mm
901 3/32 0.056 0.185 ± .005 1.42 4.7 ± .13
902 1/8 0.064 0.239 ± .005 1.63 6.07 ± .13
903 3/16 0.064 0.301 ± .005 1.63 7.65 ± .13
904 1/4 0.072 0.351 ± .005 1.83 8.92 ± .13
905 5/16 0.072 0.414 ± .005 1.83 10.52 ± .13
906 3/8 0.078 0.468 ± .005 1.98 11.89 ± .13
907 7/16 0.082 0.53 ± .007 2.08 13.46 ± .18
908 1/2 0.087 0.644 ± .009 2.21 16.36 ± .23
909 9/16 0.097 0.706 ± .009 2.46 17.93 ± .23
910 5/8 0.097 0.755 ± .009 2.46 19.18 ± .23
911 11/16 0.116 0.863 ± .009 2.95 21.92 ± .23
912 3/4 0.116 0.924 ± .009 2.95 23.47 ± .23
913 13/16 0.116 0.986 ± .010 2.95 25.04 ± .25
914 7/8 0.116 1.047 ± .010 2.95 26.59 ± .25
916 1 0.116 1.171 ± .010 2.95 29.74 ± .25
918 1 1/8 0.116 1.355 ± .012 2.95 34.42 ± .30
920 1 1/4 0.118 1.475 ± .014 3 37.47 ± .36
924 1 1/2 0.118 1.72 ± .014 3 43.69 ± .36
928 1 3/4 0.118 2.09 ± .018 3 53.09 ± .46
932 2 0.118 2.337 ± .018 3 59.36 ± .46

SAE Flange O-Ring Size Chart

Flange o-ring sizes and corresponding dimensions are shown in the interactive table below. Dash Numbers in the left column link to their specific size filtering in our online store. The second column references the Tubing Dash Size associated with the o-ring measurements.

Dash # Tubing Dash Size CS Nominal ID Nominal OD Nominal CS Inch ID Inch Tol Inch CS mm ID mm Tol mm
210 -8 1/8 3/4 1 0.139 0.734 ± .010 3.53 18.64 ± .25
214 -12 1/8 1 1-1/4 0.139 0.984 ± .010 3.53 24.99 ± .25
219 -16 1/8 1-5/16 1-9/16 0.139 1.296 ± .012 3.53 32.92 ± .30
222 -20 1/8 1-1/2 1-3/4 0.139 1.484 ± .015 3.53 37.69 ± .38
225 -24 1/8 1-7/8 2-1/8 0.139 1.859 ± .018 3.53 47.22 ± .46
228 -32 1/8 2-1/4 2-1/2 0.139 2.234 ± .020 3.53 56.74 ± .51
232 -40 1/8 2-3/4 3 0.139 2.734 ± .024 3.53 69.44 ± .61
237 -48 1/8 3-3/8 3-5/8 0.139 3.359 ± .024 3.53 85.32 ± .61
241 -56 1/8 3-7/8 4-1/8 0.139 3.859 ± .028 3.53 98.02 ± .71
245 -64 1/8 4-3/8 4-5/8 0.139 4.359 ± .030 3.53 110.72 ± .76
253 -80 1/8 5-3/8 5-5/8 0.139 5.359 ± .035 3.53 136.12 ± .89