Thread: Mini excavator centre pivot/swivel help

You can also assume that it will be imperial O-rings.
They come in standard cross sections, 1.78mm 1/16" 3.5mm 1/8", 5.33 3/16", and 6.99mm 1/4", (Difference between metric and nominal Inch sizing is the crush)

Measure the ID based on the shaft and then pick a cross section that will make then snug in the outside of the grove.
You may need PTFE back up as well either side of the oring.

https://www.sealinnovations.co.nz/

Assuming imperial due to the age and most hydraulic stuff is imperial with the exceptions of cylinders on mobile plant Excavators etc from Asia/Japan.
Z