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AS568-474 O-Ring Size
400 series · 1/4" cross section · Industrial flanges and piping
Inside diameter × cross section
520.07 × 6.99 mm
20.475″ × 0.275″ ·
outside diameter 534.03 mm (21.025″)
Dimensions
| Dimension | Inches | Millimetres |
|---|---|---|
| Inside diameter (ID) | 20.475″ | 520.07 mm |
| Cross section (CS) | 0.275″ | 6.99 mm |
| Outside diameter (OD) | 21.025″ | 534.03 mm |
Outside diameter is not measured, it is derived: OD = ID + 2 × CS.
If your measured OD disagrees with this, trust the ID and cross section — measuring
across the outside of a flexible ring is the least reliable of the three.
If you measured a used one
A ring pulled out of service will measure smaller than 520.07 mm, because compression set is permanent. If your measurement came in a little under this and the cross section roughly matches, -474 is very likely still the correct part. Ordering the size your worn ring measures is how the same failure repeats. More on this →
Nearby sizes in the 400 series
These share the same 1/4" cross section, so if the thickness is right but the diameter is off, your ring is probably one of these.
| Dash | ID (mm) | ID (in) | OD (mm) |
|---|---|---|---|
| -473 | 507.37 | 19.975″ | 521.34 |
| -475 | 532.76 | 20.975″ | 546.74 |
| -472 | 494.67 | 19.475″ | 508.64 |
| -471 | 481.97 | 18.975″ | 495.94 |