AS568-390 O-Ring
Inside diameter 20.955″
Cross-section 0.210″
Outside diameter 21.375″
Metric (ID × CS) 532.26 × 5.33 mm
OD is derived: ID + 2 × CS = 20.955″ + 2 × 0.210″ = 21.375″.
Neighboring sizes (CS 0.210″ series)
| Dash | ID | OD | ID mm | vs -390 |
|---|---|---|---|---|
| -388 | 18.955″ | 19.375″ | 481.46 | ID −2.000″ |
| -389 | 19.955″ | 20.375″ | 506.86 | ID −1.000″ |
| -390 | 20.955″ | 21.375″ | 532.26 | — |
| -391 | 21.955″ | 22.375″ | 557.66 | ID +1.000″ |
| -392 | 22.940″ | 23.360″ | 582.68 | ID +1.985″ |
Same ID, other cross-sections
- AS568-470 — same 20.955″ ID with a 0.275″ cross-section (OD 21.505″)