Thread: Stupid question: Do gas regulators have a use-by date?

I think if you look at the size range stocked and supplied by http://www.ludowicisealsonline.com/ you quickly come to realise that between metric and imperial sizes and range of fit of each of those sizes, there is no such thing as a "standard size" O-ring.
I found this mob when trying to match the O-rings in 30+ year old Hondas that I restore. I had no trouble matching all the 'odd' sizes used by Honda back then to ensure their spares sales - now of course largely NLA (no longer available)....

This is a good resource to keep handy for all sorts of things.