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AS568-326 O-Ring Size
300 series · 3/16" cross section · Heavy hydraulics, higher pressure
Inside diameter × cross section
40.64 × 5.33 mm
1.6″ × 0.21″ ·
outside diameter 51.31 mm (2.02″)
Dimensions
| Dimension | Inches | Millimetres |
|---|---|---|
| Inside diameter (ID) | 1.6″ | 40.64 mm |
| Cross section (CS) | 0.21″ | 5.33 mm |
| Outside diameter (OD) | 2.02″ | 51.31 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 40.64 mm, because compression set is permanent. If your measurement came in a little under this and the cross section roughly matches, -326 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 300 series
These share the same 3/16" 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) |
|---|---|---|---|
| -325 | 37.47 | 1.475″ | 48.13 |
| -327 | 43.81 | 1.725″ | 54.48 |
| -324 | 34.29 | 1.35″ | 44.96 |
| -328 | 46.99 | 1.85″ | 57.66 |