Re: Dull Razors

[brian whatcott <inet@INTELLISYS.NET>]

At 14:03 9/24/99 -0600, you wrote:
> a steel blade (even stainless steel) is much harder
> and tougher than any body hair (even women's under arm hair),
> so how is it that cutting hair can dull the bade?
>
> Jim Green

Folks who don't get into machining metals or wood are often
surprised to find that a lathe tool which is turning a metal
cylinder to a smaller diameter, a process of bringing the metal
past its yield point, goes better if the tool is lubricated.

In the case of wood working, where liquids are often injurious,
it is also the practise to use intensely hard edged tools - carbide
inserts are to be found on your circular saw, if you do much
ripping of planks. On your plane, it is necessary to rewhet the
 blade quite frequently.

The proteinacious keratins which Jim tends to dismiss, are
much the same material as turtleshell, or elephant tusk.

Being hard is no insurance against wear - favored bearing
 combinations are often hard against soft it's true, but
both surfaces wear, as you may notice when a rebuilt engine
for your SUV features a reground crankshaft.
 These reground bearings have worn down on a ridulously soft
lead tin indium matrix called a 'plain shell bearing'and then
 only when the oil film has broken.



brian whatcott <inet@intellisys.net>
Altus OK