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

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

These seem most common:

For background information, see O-Rings.

O-Rings are available in five different materials from Scientific
Instrument Services. Each type has its advantages and disadvantages as
listed in the O Ring Comparison Chart. Of the various types of O-Rings
available from SIS, Buna-N is the most sidely used type of O ring in
the seal ring. It is also the least expensive type of O-Ring seal. It
does however have severe temperature and chemical resistance
limitations.

NITRILE OR BUNA N (NBR) Typical Trade Names:

Chemigum Goodyear Tire & Rubber Co.
Paracril Uniroyal
Hyvcar Goodrich Chemical Co.
Krynac Polysar, Ltd.
Ny Syn Copolymer Rubber & Chem. Corp.
Buna N or Nitrile, is a copolymer of butadiene and acrylonitrile.
Acrylonitrile content is varied in commercial products from 18% to 48%.
As the nitrile content increases, resistance to petroleum base oils and
hydrocarbon fuels increases, but low temperature flexibility decreases.
Due to its excellent resistance to petroleum products, and its ability
to be compounded for service over a temperature range of -65 to + 275
degrees F (- 54 to +135 degrees C), Nitrile is the most widely used
etastomer in the seal industry today. Most military rubber
specifications for fuel and oil resistant MS and AN 0-rings require
nitrile base compounds. It should be mentioned, however, that to obtain
good resistance to low temperature with nitrile compounding, it is
almost always necessary to sacrifice some high temperature fuel and oil
resistance. Nitrile compounds are superior to most elastomers with
regard to compression set or cold flow, tear and abrasion resistance.
Inherently, they do possess good resistance to ozone, sunlight or
weather but this can be substantially improved through compounding.
However, since ozone and weather resistance are not always built in,
seals from nitrile bases should not be stored near electric motors or
other equipment which may generate ozone, or in direct sunlight.

Nitrile Is Recommended for:

General purpose sealing.
Petroleum oils and fluids.
Cold Water.
Silicone greases and oils
Di-ester base lubricants (MIL-L-7808).
Ethylene glycol base fluids (Hydrolubes)
Nitrile is not recommended for:

Halogenated hydrocarbons (carbon tetrachloride, trichloroethylene)
Nitro hydrocarbons (nitrobenzene, aniline)
Phosphate ester hydraulic fluids (Skydrol, Fyrquel, Pydraul).
Ketones (MEK, acetone)
Strong Acids Ozone
Automotive brake fluid.


--------------------------------------------------------------------------------

O-Rings are available in sizes (sizes 0, 1, 2 and 3) which correspond
to the diameter of the cross section of the O-Ring. Within these groups
the O-Rings are classified according to their inside diameter. To see a
complete selection of the various sizes and types of O-Rings available
from Scientific Instrument Services, just click on the hyperlink on the
size list above. If the size you require is not listed, it may still be
available. Contact us with your requirements.

Although I've not done business with these folks before.

dennis
in nca

On Sat, 11 Mar 2006 16:36:07 GMT, 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

All you ever wanted to know about O-rings, including recommended
materials for various applications. in this downloadable handbook:

http://www.thesealman.com/pages/orin...ook/index.html

It's about 11 megs.

On Sat, 11 Mar 2006 11:17:35 -0600, Don Foreman
wrote:

On Sat, 11 Mar 2006 16:36:07 GMT, 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

All you ever wanted to know about O-rings, including recommended
materials for various applications. in this downloadable handbook:

http://www.thesealman.com/pages/orin...ook/index.html

It's about 11 megs.


Thanks!

Gunner



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

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.

I think Viton is hard to beat as the best general purpose material to
stock. More expensive than Buna or nitrile but much more chemically
resistant when you need that. I don't think I've ever run into an
application that called for Buna or nitrile that Viton wouldn't work in,
and I've had several applications that called for Viton either for
chemical resistance or high temperatures or low outgassing in a vacuum
system. Probably safe for a year or three in a truck toolbox, at least.
It will eventually start to check and then crack when you flex it so it
will be pretty obvious when it's time to toss them. The Parker catalog
is a great resource on materials and especially on oring groove design.
www.mcmaster.com has a great selection, as well as www.sisweb.com (as
someone else mentioned - I've bought several items from them over the
years and think a lot of them, but I am friends with the owners :-)).

--
Regards,
Carl Ijames carl.ijames at verizon.net

On Sun, 12 Mar 2006 04:30:49 GMT, "Carl Ijames"
wrote:

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.

I think Viton is hard to beat as the best general purpose material to
stock. More expensive than Buna or nitrile but much more chemically
resistant when you need that. I don't think I've ever run into an
application that called for Buna or nitrile that Viton wouldn't work in,
and I've had several applications that called for Viton either for
chemical resistance or high temperatures or low outgassing in a vacuum
system. Probably safe for a year or three in a truck toolbox, at least.
It will eventually start to check and then crack when you flex it so it
will be pretty obvious when it's time to toss them. The Parker catalog
is a great resource on materials and especially on oring groove design.
www.mcmaster.com has a great selection, as well as www.sisweb.com (as
someone else mentioned - I've bought several items from them over the
years and think a lot of them, but I am friends with the owners :-)).

Thanks Carl..exactly the sort of answer I was looking for.

Respects

Gunner



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

"Gunner" wrote in message
...
On Sun, 12 Mar 2006 04:30:49 GMT, "Carl Ijames"
wrote:

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.

I think Viton is hard to beat as the best
general purpose material to
stock. More expensive than Buna or nitrile but
much more chemically
resistant when you need that. I don't think
I've ever run into an
application that called for Buna or nitrile that
Viton wouldn't work in,
and I've had several applications that called
for Viton either for
chemical resistance or high temperatures or low
outgassing in a vacuum
system. Probably safe for a year or three in a
truck toolbox, at least.
It will eventually start to check and then crack
when you flex it so it
will be pretty obvious when it's time to toss
them. The Parker catalog
is a great resource on materials and especially
on oring groove design.
www.mcmaster.com has a great selection, as well
as www.sisweb.com (as
someone else mentioned - I've bought several
items from them over the
years and think a lot of them, but I am friends
with the owners :-)).

Thanks Carl..exactly the sort of answer I was
looking for.

Respects

Gunner



I agree with Carl. The Viton "o" rings are pretty
much impervious to most common oils and common
industrial chemicals. The extra cost will be
repaid in reliability. If you want to maximise the
shelf life of them, keep them in a dark, sealed
container.

Tom

I agree with Carl. The Viton "o" rings are pretty much impervious to most
common oils and common industrial chemicals. The extra cost will be repaid
in reliability.

Yes, until you need to make a "special" by cutting out a section and
re-joining it. Cyanoacrylate (super-glue) works surprisingly well with
natural or nitrile rubber, but it won't work with viton (or silicone).

On Sun, 12 Mar 2006 12:11:11 -0000, "Newshound"
wrote:

I agree with Carl. The Viton "o" rings are pretty much impervious to most
common oils and common industrial chemicals. The extra cost will be repaid
in reliability.

Yes, until you need to make a "special" by cutting out a section and
re-joining it. Cyanoacrylate (super-glue) works surprisingly well with
natural or nitrile rubber, but it won't work with viton (or silicone).


I use viton exclusively, I'm in the chemistry dept. at a university.
Also, you know you can buy o-ring cord stock for making your own
special sizes. I've got a little teflon V block for aligning the ends.
I should make a fixture to make square end cuts with a razor blade
too.
Randy Replogle
--
Randy Replogle

On Sun, 12 Mar 2006 06:12:27 GMT, Gunner
wrote:

On Sun, 12 Mar 2006 04:30:49 GMT, "Carl Ijames"
wrote:

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.

I think Viton is hard to beat as the best general purpose material to
stock. More expensive than Buna or nitrile but much more chemically
resistant when you need that. I don't think I've ever run into an
application that called for Buna or nitrile that Viton wouldn't work in,
and I've had several applications that called for Viton either for
chemical resistance or high temperatures or low outgassing in a vacuum
system. Probably safe for a year or three in a truck toolbox, at least.
It will eventually start to check and then crack when you flex it so it
will be pretty obvious when it's time to toss them. The Parker catalog
is a great resource on materials and especially on oring groove design.
www.mcmaster.com has a great selection, as well as www.sisweb.com (as
someone else mentioned - I've bought several items from them over the
years and think a lot of them, but I am friends with the owners :-)).

Thanks Carl..exactly the sort of answer I was looking for.

Respects

Gunner


I just look in my Parker O-ring book, chemical compatibility section.
I work in the chemical industry. Viton will go to hell in a
handbasket if it sees an amine. EPDM is very good. Buna is fine for
some stuff. I hate Kalrez and won't use it unless I positively have
to (temperatures above high temp silicone).

Look in Section 7 of this link:
http://www.parker.com/o-ring/Literature/ORD5700.pdf . It starts on
Page 163.

Pete Keillor

"Carl Ijames" wrote:

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?



http://www.parker.com/o-ring/Literature/00-5700.pdf

More than you ever wanted to know about O-rings :-)

--
Email reply: please remove one letter from each side of "@"
Spammers are Scammers. Exterminate them.

Go to your local diesel fuel injection shop. They usually have to throw a
lot of extras away. Good quality O'rings.

I wonder what material one could expect from the Harbor Freight kit.
Sort of scary to think about it.
I have dozens of Buna-N and Viton O rings that have been stored in a
drawer for at least 15 years at room temp and none of them show any
degradation. And when I take apart hydraulic cylinders that have been
operating for 20 to 40 years, I don't see a lot of degradation either.
Many of these systems run at elevated temperatures, so I don't see why
storing them in the back of the truck would be a problem.

Pete Stanaitis
----------------

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

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

On 12 Mar 2006 09:22:44 -0800, "
wrote:

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.


Somebody (Parker?) sells a graduated cone for this. Probably
expensive.
--
Randy Replogle

On Sat, 11 Mar 2006 16:36:07 GMT, 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

What general sizes are needing?

On Sun, 12 Mar 2006 21:49:52 -0600, Andy Asberry
wrote:

On Sat, 11 Mar 2006 16:36:07 GMT, 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

What general sizes are needing?


Thats the problem...I never know. Last week I needed some tiny ones
for the inside of a Hardinge Auto-threader..2 weeks before that..some
that were about 5/8" in diameter for a hydraulic unit..a month before
that..

Which is why I need to keep an assortment on hand. Like OD & ID snap
rings. and the occasional E clip.

If I were bringing the machines to my shop for repair..I could keep a
****load of stuff on hand ..but since I work out of my truck....it
becomes a bit more problematic.

And there is another bitch of mine..snap rings. They are hard to find
since the end of the old time hardware store..and the bearing houses
are more than happy to sell you some, assuming they have any...but
will only sell you a full bag of 20is or so.

And I hate driving 50 miles round trip to the nearest place that sells
snap rings, even in So. California...for a single snap ring.

Gunner



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