AS568-259 O-Ring

Inside diameter 6.234″
Cross-section 0.139″
Outside diameter 6.512″
Metric (ID × CS) 158.34 × 3.53 mm

OD is derived: ID + 2 × CS = 6.234″ + 2 × 0.139″ = 6.512″.

Neighboring sizes (CS 0.139″ series)

Dash ID OD ID mm vs -259
-257 5.859″ 6.137″ 148.82 ID −0.375″
-258 5.984″ 6.262″ 151.99 ID −0.250″
-259 6.234″ 6.512″ 158.34
-260 6.484″ 6.762″ 164.69 ID +0.250″
-261 6.734″ 7.012″ 171.04 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.