AS568-239 O-Ring

Inside diameter 3.609″
Cross-section 0.139″
Outside diameter 3.887″
Metric (ID × CS) 91.67 × 3.53 mm

OD is derived: ID + 2 × CS = 3.609″ + 2 × 0.139″ = 3.887″.

Neighboring sizes (CS 0.139″ series)

Dash ID OD ID mm vs -239
-237 3.359″ 3.637″ 85.32 ID −0.250″
-238 3.484″ 3.762″ 88.49 ID −0.125″
-239 3.609″ 3.887″ 91.67
-240 3.734″ 4.012″ 94.84 ID +0.125″
-241 3.859″ 4.137″ 98.02 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.