AS568-266 O-Ring

Inside diameter 7.984″
Cross-section 0.139″
Outside diameter 8.262″
Metric (ID × CS) 202.79 × 3.53 mm

OD is derived: ID + 2 × CS = 7.984″ + 2 × 0.139″ = 8.262″.

Neighboring sizes (CS 0.139″ series)

Dash ID OD ID mm vs -266
-264 7.484″ 7.762″ 190.09 ID −0.500″
-265 7.734″ 8.012″ 196.44 ID −0.250″
-266 7.984″ 8.262″ 202.79
-267 8.234″ 8.512″ 209.14 ID +0.250″
-268 8.484″ 8.762″ 215.49 ID +0.500″
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.