AS568-158 O-Ring

Inside diameter 4.737″
Cross-section 0.103″
Outside diameter 4.943″
Metric (ID × CS) 120.32 × 2.62 mm

OD is derived: ID + 2 × CS = 4.737″ + 2 × 0.103″ = 4.943″.

Neighboring sizes (CS 0.103″ series)

Dash ID OD ID mm vs -158
-156 4.237″ 4.443″ 107.62 ID −0.500″
-157 4.487″ 4.693″ 113.97 ID −0.250″
-158 4.737″ 4.943″ 120.32
-159 4.987″ 5.193″ 126.67 ID +0.250″
-160 5.237″ 5.443″ 133.02 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.