AS568-209 O-Ring

Inside diameter 0.671″
Cross-section 0.139″
Outside diameter 0.949″
Metric (ID × CS) 17.04 × 3.53 mm

OD is derived: ID + 2 × CS = 0.671″ + 2 × 0.139″ = 0.949″.

Neighboring sizes (CS 0.139″ series)

Dash ID OD ID mm vs -209
-207 0.546″ 0.824″ 13.87 ID −0.125″
-208 0.609″ 0.887″ 15.47 ID −0.062″
-209 0.671″ 0.949″ 17.04
-210 0.734″ 1.012″ 18.64 ID +0.063″
-211 0.796″ 1.074″ 20.22 ID +0.125″
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.