I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow

How about $60.00?

http://www.pegasusautoracing.com/Pro....asp?RecId=349

- -
Rex Burkheimer


Eric R Snow wrote:
I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow

"Eric R Snow" wrote in message
...
I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he
needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since
it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow

I've got one at work, but it's been years since I've looked at it. You
might be able to find the ASTM test standard and get a description
from that, or maybe something from the RMA (Rubber Manufacturers
Association)


Wish I could have been more help

On Wed, 06 Jul 2005 10:47:02 -0700, the renowned Eric R Snow
wrote:

I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow

I don't have a tester, but it looks like you can really easily make an
indenter like this (type A) and press it against the material with
1.81 lbs of force and read the indentation in inches as 100 (no
penetration) to 0 (100 thou penetration).

http://www.ptc1.com/durometers_tech.htm

Dimensions of the indenter are given in metric here as:

Hardened steel rod 1,10 mm - 1,14 mm dia,
with a truncated 35º cone, 0,79 mm dia.

http://www.npl.co.uk/force/guidance/...ss/rubber.html

Confirmed here in this data sheet for a commercial durometer:

http://www.checkline.com/products/12...abf472340604e5



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On Wed, 06 Jul 2005 10:47:02 -0700, Eric R Snow
wrote:

I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow

Perhaps you could use a dial indicator with a spring and either a
conical or ball foot.

http://www.gordonengland.co.uk/hardness/scleroscope.htm

Find a material specimen of known durometer that most closely matches
the measurement on the part to be matched.

On Wed, 06 Jul 2005 15:17:53 -0400, Spehro Pefhany
wrote:

On Wed, 06 Jul 2005 10:47:02 -0700, the renowned Eric R Snow
wrote:

I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow

I don't have a tester, but it looks like you can really easily make an
indenter like this (type A) and press it against the material with
1.81 lbs of force and read the indentation in inches as 100 (no
penetration) to 0 (100 thou penetration).

http://www.ptc1.com/durometers_tech.htm

Dimensions of the indenter are given in metric here as:

Hardened steel rod 1,10 mm - 1,14 mm dia,
with a truncated 35º cone, 0,79 mm dia.

http://www.npl.co.uk/force/guidance/...ss/rubber.html

Confirmed here in this data sheet for a commercial durometer:

http://www.checkline.com/products/12...abf472340604e5



Best regards,
Spehro Pefhany
Thanks Spehro,
I googled but did not find the above sites.
Cheers,
Eric

On Wed, 06 Jul 2005 14:24:32 -0500, Don Foreman
wrote:

On Wed, 06 Jul 2005 10:47:02 -0700, Eric R Snow
wrote:

I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow

Perhaps you could use a dial indicator with a spring and either a
conical or ball foot.

http://www.gordonengland.co.uk/hardness/scleroscope.htm

Find a material specimen of known durometer that most closely matches
the measurement on the part to be matched.




Don, Thanks for the link. If I had a known sample it would be easy.
But the only samples I have are the ones I need to measure. Thanks for
the link.
Eric

o-rings are available in 70 durometer and 90 durometer in Buna - n

in fluorocarbon or viton they are 75 durometer


were I in your shoes I would take the parts down to the local rubber and
gasket house
they should have a variety of known materials to compare it to and might
have a tester

"Eric R Snow" wrote in message
...
I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow


Eric
I have in my desk a set of urethane samples (1" Diameter) of different
durometers from http://www.acrotechinc.com/. It has the following durometer
samples: 40A, 60A, 80A, 90A, 95A, and 75D. I don't know if your rubber is in
that range or not. Write to them and ask for one, or if you really want I
can mail this one to you. I live just across the sound from you.

Another idea; where ever you got the rubber from that you want to measure
should be able to tell you all you want to know about it, shouldn't they?

Lane

Eric R Snow wrote:
I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow
Measuring durometer, even with a meter specifically designed to so, is
very subjective. Different part shapes and thicknesses can almost make
it a guessing game. We use ours only to compare o-rings of the same size
and hardness. The same goes for checking sheet stock.
Go to http://www.mcmaster.com/ and search "rubber hardness". You will
find a rough comparison chart and also a sample kit for about $10.

On Wed, 06 Jul 2005 19:43:00 -0400, tomcas
wrote:

Eric R Snow wrote:
I need to get the durometer tested on a rubber part. This part just
came in, the customer doesn't know what the durometer is, and he needs
parts friday. I would just order a durometer overnight but the
cheapest I can find is $280.00. The whole job isn't worth it. Since it
may or may not turn into more work, I'm reluctant to spend the money
on it. The customer said I only need to be close, not perfect on the
hardness. Is there a way I can approximate it with a weight and a
properly shaped probe tip?
Thanks,
Eric R Snow
Measuring durometer, even with a meter specifically designed to so, is
very subjective. Different part shapes and thicknesses can almost make
it a guessing game. We use ours only to compare o-rings of the same size
and hardness. The same goes for checking sheet stock.
Go to http://www.mcmaster.com/ and search "rubber hardness". You will
find a rough comparison chart and also a sample kit for about $10.
Thanks everybody for the responses. After posting I looked at ebay and
found two that were reasonable. I ended up getting both. I will order
the sample from McMaster Carr. But I will also be ordering the rubber
sheet at the same time. Now that I live on an island it is hard to
some stuff done fast. Like going to a local rubber supplier and asking
them to measure the sample. That trip would end up being at least 4
hours round trip because of ferries and traffic.
ERS