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AS568-040 O-Ring Size

000 series · 1/16" cross section · Pneumatics, instrumentation, small static seals

Inside diameter × cross section 72.75 × 1.78 mm 2.864″ × 0.07″ · outside diameter 76.3 mm (3.004″)

Dimensions

DimensionInchesMillimetres
Inside diameter (ID)2.864″ 72.75 mm
Cross section (CS)0.07″ 1.78 mm
Outside diameter (OD)3.004″ 76.3 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 72.75 mm, because compression set is permanent. If your measurement came in a little under this and the cross section roughly matches, -040 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 000 series

These share the same 1/16" cross section, so if the thickness is right but the diameter is off, your ring is probably one of these.

DashID (mm)ID (in)OD (mm)
-03969.572.739″73.13
-04175.922.989″79.48
-03866.42.614″69.95
-03763.222.489″66.78