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Re: Tungsten

Original poster: "Gerald  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

OK, now I must ask. The green tipped tungsten rods that I bought and thought were pure tungsten certainly don't seem soft and malable. In fact, they are very brittle and hard. The red tipped tungsten rods, I believe, are the ones that have thorium (did I remember this right) and are slightly radioactive. So how pure are the green ones and how "very pure" does tungsten need to be to be soft and malable???

Gerry R.



Original poster: BunnyKiller <bunikllr@xxxxxxx>

You have a "point" there David.... there are three items used to test for Rockwell Hardness 1 a diamond point or 2 a tungsten carbide point and thirdly in line a tungsten point... so can it be said???
that tungsten ( in pure form? ) is the 3rd hardest material around???
( well lets exclude Ruby since it is almost electronically inert as far as electron transfer) If I remeber my metalurgy correctly, ther are some exotics that have some superior characteristics ( hardness, melt points, densities etc) but why arent they used as the "point" in a Rockwell Hardness test?? Obviously tungsten has a crystalline matrix that can be considerd "very bonded" on the molecular scale. Maybe this is why we prefer to use tungsten as an electrode ... if diamonds were that cheap and easily shaped, I believe we would be using diamond rods as spark gap material instead of tungsten... ( diamonds are deciently conductive IIRC) we need to develope a new element that has strong electron bonding but with enuf free electrons available to transfer enuf current without destroying the original "linking" structure of the host material... and especially at the Ev of such material being abused.... hmmm sounds vaigly ( spelling) famailiar to SuperConductive materials at near 0 degree Kelvin.... uhoh off topic now ....

but it would be kewl     0 degree Bucky Ball rods for spark gaps ..
imagine  0 ohms resitance ...   so much for spark gap loss  ;)

Scot D



Tesla list wrote:

Original poster: DRIEBEN@xxxxxxxxxxxxxxx
Jared, Gary,

I'm sorry, but I'm gonna have to go with Gary
on this. "Pure" tungsten has a melting point
of ~6170*F and a specific gravity of 19.3 and
I just can't see anything with those properties
being "softer than lead" which has a melting
point of a mere 621*F, BTW. Of course mercury
has a specific gravity of 13.5 but is liquid
at room temp (-38*F is its melting point, I believe).
Maybe some of the more chemically inclined list
members could jump in on settling the hardness
scale that pure tungsten would fall into.

David Rieben