"jeff" wrote in message
...
On Wed, 5 Jan 2011 14:30:14 -0800, "Edward Hennessey"
wrote:


I once had the pleasure of quarrying alongside a
delightful gentleman wielding what he said was a
self-sharpening pick with a 12 pound head. Though
I did not investigate the particulars of the tool
at the time--except to note that both striking ends
remained exceptionally keen in extended use and
necessarily wore protective covers when we adjourned
for the night--dulling experience with my own tools
gave later pause to ruminate on its makeup.

My over-thinking speculation was that a tool with
progressively softer layers of steel alloys radiating
out from the harder core could form the material for
such an implement. But my Internet searches over time
for either a historical exemplar, available modern
pick or other excavating hand tool of such self-sharpening
nature proved unavailing.

An immediate and unexpected stimulus to this post was
a provocative article on the discovery of self-sharpening
teeth in sea urchins, the text of which appeared in
"Science Daily" seen at:

http://www.sciencedaily.com/releases...1222162404.htm


The urchin teeth differ from my naive preconception in
that the hard hard layers in the structure all of the same
durability among which are interspersed eroding soft layers.

This idea and its reality is elegant for simplicity.
Because the leading striking edge of a penetrating implement
wears first and the most during use, it is now clear how this
would result in a taper both in a pick and urchin tooth.

If anyone can either generally corroborate and specifically
describe occurrences of such self-sharpening mining tools (a
hefty pick foremost) or give me a pointer to any current
manufacturers whom might provide more information or the
implements themselves, I would be grateful.

Advance thanks to all for any direction.

Regards,

Edward Hennessey

This may not be of any use to you but I do belong to a Mineral
Society
and in all the outings I've ever been on the hammer of choice and
the
one I also use is this unit (Estwing E3-22P 22-Ounce Rock Pick).
This thing stays fairly sharp considering that you are breaking
rocks
with it but It does seem to hold it point very well. Double
pointed
12 pound hammer swung all day would be a serious workout...

J:

The sledges we use for remote heavy work toll 16 and 20 pounds.
A day with them is a hump but there are fewer days on a project when
rock feels that kind of weight. Handle vibration and the resultant
trigger
finger pathology by transmitted vibration remains a menace we temper
by
sleeving the handles with shock-absorbing foam and tethering the
shafts to the wrist. Releasing the grip right before impact diminishes
physical
problems radically. After practice, you get good at it...and thankful.

We agree on Estwings being good tools. For smaller stuff, they are
superb.
Not recalling model designations, their crack hammers and the mason's
style heads earn a place in the trucks.

Thanks for the comment.

Regards,

Edward Hennessey