We recently received a batch of custom cable (7,500 meters of it!) that has too 
hard and stiff a jacket for us to use. We had failed to specify the jacket 
durometer, so the vendor used whatever they had.

We then got a sample of a much less stiff cable, and this vendor specified 
"Shore A 68 Durometer". I got doing some research on this and it's pretty 
interesting:

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

Essentially you have an important material property that is so far from any 
fundamental physical property such as mass or length that it is specified 
purely empirically -- put a special indenting tool on the material and see how 
far it dents.

Nonetheless, the web site above does spec everything in metric units.

More interesting info at http://www.machinist-materials.com/hardness.htm, 
comparing the different hardness scales. Even this US site is pretty much all 
metric.

Jim

P.S. anyone need 7.5 km of cheap ethernet-ready cable?




Jim Elwell
[EMAIL PROTECTED]
801-466-8770
www.qsicorp.com

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