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AS568-372 O-Ring Size
300 series · 3/16" cross section · Heavy hydraulics, higher pressure
Inside diameter × cross section
221.61 × 5.33 mm
8.725″ × 0.21″ ·
outside diameter 232.28 mm (9.145″)
Dimensions
| Dimension | Inches | Millimetres |
|---|---|---|
| Inside diameter (ID) | 8.725″ | 221.61 mm |
| Cross section (CS) | 0.21″ | 5.33 mm |
| Outside diameter (OD) | 9.145″ | 232.28 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 221.61 mm, because compression set is permanent. If your measurement came in a little under this and the cross section roughly matches, -372 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) |
|---|---|---|---|
| -371 | 215.26 | 8.475″ | 225.93 |
| -373 | 227.96 | 8.975″ | 238.63 |
| -370 | 208.91 | 8.225″ | 219.58 |
| -374 | 234.31 | 9.225″ | 244.98 |