AS568-129 O-Ring

Inside diameter 1.549″
Cross-section 0.103″
Outside diameter 1.755″
Metric (ID × CS) 39.34 × 2.62 mm

OD is derived: ID + 2 × CS = 1.549″ + 2 × 0.103″ = 1.755″.

Neighboring sizes (CS 0.103″ series)

Dash ID OD ID mm vs -129
-127 1.424″ 1.630″ 36.17 ID −0.125″
-128 1.487″ 1.693″ 37.77 ID −0.062″
-129 1.549″ 1.755″ 39.34
-130 1.612″ 1.818″ 40.94 ID +0.063″
-131 1.674″ 1.880″ 42.52 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.