AS568-128 O-Ring

Inside diameter 1.487″
Cross-section 0.103″
Outside diameter 1.693″
Metric (ID × CS) 37.77 × 2.62 mm

OD is derived: ID + 2 × CS = 1.487″ + 2 × 0.103″ = 1.693″.

Neighboring sizes (CS 0.103″ series)

Dash ID OD ID mm vs -128
-126 1.362″ 1.568″ 34.59 ID −0.125″
-127 1.424″ 1.630″ 36.17 ID −0.063″
-128 1.487″ 1.693″ 37.77
-129 1.549″ 1.755″ 39.34 ID +0.062″
-130 1.612″ 1.818″ 40.94 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.