Home › AS568-161
AS568-161 O-Ring Size
100 series · 3/32" cross section · Hydraulics, pumps, valves
Inside diameter × cross section
139.37 × 2.62 mm
5.487″ × 0.103″ ·
outside diameter 144.6 mm (5.693″)
Dimensions
| Dimension | Inches | Millimetres |
|---|---|---|
| Inside diameter (ID) | 5.487″ | 139.37 mm |
| Cross section (CS) | 0.103″ | 2.62 mm |
| Outside diameter (OD) | 5.693″ | 144.6 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 139.37 mm, because compression set is permanent. If your measurement came in a little under this and the cross section roughly matches, -161 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) |
|---|---|---|---|
| -160 | 133.02 | 5.237″ | 138.25 |
| -162 | 145.72 | 5.737″ | 150.95 |
| -159 | 126.67 | 4.987″ | 131.9 |
| -163 | 152.07 | 5.987″ | 157.3 |