AS568-284 O-Ring

Inside diameter 17.955″
Cross-section 0.139″
Outside diameter 18.233″
Metric (ID × CS) 456.06 × 3.53 mm

OD is derived: ID + 2 × CS = 17.955″ + 2 × 0.139″ = 18.233″.

Neighboring sizes (CS 0.139″ series)

Dash ID OD ID mm vs -284
-282 15.955″ 16.233″ 405.26 ID −2.000″
-283 16.955″ 17.233″ 430.66 ID −1.000″
-284 17.955″ 18.233″ 456.06

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.