AS568-231 O-Ring

Inside diameter 2.609″
Cross-section 0.139″
Outside diameter 2.887″
Metric (ID × CS) 66.27 × 3.53 mm

OD is derived: ID + 2 × CS = 2.609″ + 2 × 0.139″ = 2.887″.

Neighboring sizes (CS 0.139″ series)

Dash ID OD ID mm vs -231
-229 2.359″ 2.637″ 59.92 ID −0.250″
-230 2.484″ 2.762″ 63.09 ID −0.125″
-231 2.609″ 2.887″ 66.27
-232 2.734″ 3.012″ 69.44 ID +0.125″
-233 2.859″ 3.137″ 72.62 ID +0.250″
Data provenance. SAE AS568, Aerospace Size Standard for O-rings (SAE International). Nominal dimensions per AS568; size tolerances vary by dash number and are not yet cataloged. Groove/gland design depends on the application — consult a gland design reference. See all data sources.