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AS568-458 O-Ring Size
400 series · 1/4" cross section · Industrial flanges and piping
Inside diameter × cross section
316.86 × 6.99 mm
12.475″ × 0.275″ ·
outside diameter 330.83 mm (13.025″)
Dimensions
| Dimension | Inches | Millimetres |
|---|---|---|
| Inside diameter (ID) | 12.475″ | 316.86 mm |
| Cross section (CS) | 0.275″ | 6.99 mm |
| Outside diameter (OD) | 13.025″ | 330.83 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 316.86 mm, because compression set is permanent. If your measurement came in a little under this and the cross section roughly matches, -458 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) |
|---|---|---|---|
| -457 | 304.16 | 11.975″ | 318.13 |
| -459 | 329.56 | 12.975″ | 343.53 |
| -456 | 291.46 | 11.475″ | 305.44 |
| -460 | 342.26 | 13.475″ | 356.24 |