Hi David,

have a look at:

http://www.barnwell.co.uk/pdf/O%20Rings.pdf

That has all the info for sizing grooves etc for O rings.

I don't know what you will be using the O ring for, but for steam use these
groove sizes give too tight a fit and can be made deeper. This makes the O ring
much freer and extends it's life considerably. For use as piston rings, the
piston should move freely with very little effort when the ring is fitted.

I'm tending to move away from O rings and fit PTFE rings and gland packings
instead. It gives a much freer running engine.

John



--- In halfinchlivesteamforum@..., david_steam <no_reply@...>
wrote:
>
> I recall somewhere seeing a 'limits and fit' table for O rings?
>
> Assuming a 1/16" O ring, if I wanted an, ID of 0.25" what depth and diameter
spotface cutting would I require?
>
> Again if the OD was the critical factor of 0.25" what would the ID have to be?
>