AS568-440 O-Ring

Inside diameter 6.725″
Cross-section 0.275″
Outside diameter 7.275″
Metric (ID × CS) 170.81 × 6.99 mm

OD is derived: ID + 2 × CS = 6.725″ + 2 × 0.275″ = 7.275″.

Neighboring sizes (CS 0.275″ series)

Dash ID OD ID mm vs -440
-438 6.225″ 6.775″ 158.11 ID −0.500″
-439 6.475″ 7.025″ 164.46 ID −0.250″
-440 6.725″ 7.275″ 170.81
-441 6.975″ 7.525″ 177.16 ID +0.250″
-442 7.225″ 7.775″ 183.51 ID +0.500″

Same ID, other cross-sections

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.