"Ignoramus18758" wrote in message
...
On 2011-05-03, Ned Simmons wrote:
On Tue, 03 May 2011 11:58:08 -0500, Ignoramus18758
wrote:

A little distraction from our "show us Obama Bin Laden's death
certificate" battles.

I was reading this article.

http://en.wikipedia.org/wiki/Depleted_uranium

It says ``According to recent research,[28] at least some of the most
promising tungsten alloys that have been considered as replacement for
depleted uranium in penetrator ammunitions, such as tungsten-cobalt or
tungsten-nickel-cobalt alloys, also possess extreme carcinogenic
properties, which by far exceed those (confirmed or suspected) of
depleted uranium itself: 100% of rats implanted with a pellet of such
alloys developed lethal rhabdomyosarcoma within a few weeks. ''

This, obviously, concerns me, since the end mills that I often use are
made of tungsten/cobalt.

Are they carcinogenic?

Any comments?

i

Any effect is most likely due to the cobalt. As far as I know, and I
do a lot of work in a plant that processes tungsten, tungsten is not a
known carcinogen. When you speak of tungsten/cobalt end mill, I assume
you mean tungsten carbide/cobalt.

Re the cobalt: http://www.lenntech.com/periodic/elements/co.htm
"Carcinogenicity- International Agency for Research on Cancer (IARC)
has listed cobalt and cobalt compounds within group 2B (agents which
are possibly carcinogenic to humans). ACGIH has placed cobalt and
inorganic compounds in category A3 (Experimental animal carcinogen-
the agent is carcinogenic in experimental animals at a relatively high
dose, by route(s), histologic type(s), or by mechanism(s) that are not
considered relevant to worker exposure.) Cobalt has been classified to
be carcinogenic to experimental animals by the Federal Republic of
Germany."

Which I take to mean, unless you're making body piercings out of old
carbide tools, don't worry about it


I believe that cheap tungsten carbide jewelry on eBay is made of
recycled end mills, with cobalt binding. The more expensive tungsten
carbide jewelry is made with nickel binding.

i

I don't know anything about jewelry, but FYI, cobalt is a lot more expensive
than nickel.

--
Ed Huntress