On 08/10/2020 09:18, fred wrote:
On Wednesday, October 7, 2020 at 9:23:52 PM UTC+1, bert wrote:
Is there by any chance a simple rule of thumb for calculating the
required size of a replacement o ring? I l looked up a supplier and they
had a chart which seemed horribly complicated.
--
bert

Try ebay for an 'O' ring set. You'll get a selectiob for very little money

True but IME they normally contain "thinner" rings and often don't have
a good match for existing ones.

If you are missing the ring altogether, your replacement should have a
bore close to the depth of the groove (slightly loose is OK), a
thickness close to the width of the groove, and it should stick out
slightly when it is in position.

They normally come in integral metric sizes, if you see what I mean.
(Same applies to imperial).