Just a couple of thoughts.

First Apple Rubber Products is another maker of Orings. Their web site
has a lot of information, probably more information than you want.
Parker and Apple both sent me some techincal literature some years back
when I needed info on how to size the Oring grooves ( and a few samples
of Orings ).

Second Harbor Freight sells assortments and also a make your own kit.
The kit is just Oring stock, adhesive, and a simple jig and razor blade
to get a nice straight cut. I would probably buy both if I were you.
I am sure Harbor Freight sell Buna N Orings.

If I recall correctly buna Orings do not have a shelf life. Not too
sure about this. It has been a while. Will check at work tomorrow.

And last but not least, you might want to turn some tapered bits of
steel similar to the things sold for sizing finger rings. I have done
this. Handy for sizing Orings, but also for measuring holes. Stick
the taper tool into the hole and then measure the diameter of the
tapered tool with a caliper flush with the surface that has the hole.
Much easier than trying to use the inside caliper measurement ears.
Good for Orings because they stay round and you measure the tapered
steel which does not distort.


Dan
Gunner wrote:
Im now needing to occasionally replace o-rings in machine tools and
whatnot and need to purchase a selection of them to keep in the truck.

Most applications will be for air, in an oily environment, though a
few will be for hydraulic fluids. Is there some material best suited
for general use?

And will they degrade in a short period of time, in the back of my
service truck in hot weather?

What material should I be using?

I will likely purchase from ebay one of those 400 piece selections
for $10 or so, unless someone has better suggestions.

Grants recent thread on O/A o rings brought this to mind.

Thanks in advance

Gunner



"A prudent man foresees the difficulties ahead and prepares for them;
the simpleton goes blindly on and suffers the consequences."
- Proverbs 22:3