AS568-004 O-Ring

Inside diameter 0.070″
Cross-section 0.070″
Outside diameter 0.210″
Metric (ID × CS) 1.78 × 1.78 mm

OD is derived: ID + 2 × CS = 0.070″ + 2 × 0.070″ = 0.210″.

Neighboring sizes (CS 0.070″ series)

Dash ID OD ID mm vs -004
-004 0.070″ 0.210″ 1.78
-005 0.101″ 0.241″ 2.57 ID +0.031″
-006 0.114″ 0.254″ 2.90 ID +0.044″
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.