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AS568-151 O-Ring Size
100 series · 3/32" cross section · Hydraulics, pumps, valves
Inside diameter × cross section
75.87 × 2.62 mm
2.987″ × 0.103″ ·
outside diameter 81.1 mm (3.193″)
Dimensions
| Dimension | Inches | Millimetres |
|---|---|---|
| Inside diameter (ID) | 2.987″ | 75.87 mm |
| Cross section (CS) | 0.103″ | 2.62 mm |
| Outside diameter (OD) | 3.193″ | 81.1 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 75.87 mm, because compression set is permanent. If your measurement came in a little under this and the cross section roughly matches, -151 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 100 series
These share the same 3/32" 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) |
|---|---|---|---|
| -150 | 72.69 | 2.862″ | 77.93 |
| -149 | 71.12 | 2.8″ | 76.35 |
| -148 | 69.52 | 2.737″ | 74.75 |
| -152 | 82.22 | 3.237″ | 87.45 |