Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only. I
don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I will
pay your listing fees.

I have a small piece, maybe 3 oz.

i

On 2007-10-19, Adam Corolla wrote:
Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only. I
don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I will
pay your listing fees.

On Fri, 19 Oct 2007 13:37:15 -0500, "Adam Corolla"
wrote:

Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

I may be able to get you a piece for something above scrap value.


Notes: I don't want tungsten carbide or other alloy--pure tungsten only. I
don't want any porous pieces, they should be solid.

As a result of the manufacturing process, tungsten is less than 100%
dense. In general, it gets denser as it's worked; e.g., pressed -
sintered - rolled - drawn.


If you're interested, we can arrange a private auction through eBay, I will
pay your listing fees.

Why not just a cash sale? Do you have a fix on the current scrap
price?

--
Ned Simmons

Adam Corolla wrote:
Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only. I
don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I will
pay your listing fees.

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.

"Ned Simmons" wrote in message
...
On Fri, 19 Oct 2007 13:37:15 -0500, "Adam Corolla"
wrote:

Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

I may be able to get you a piece for something above scrap value.


Fair enough.


As a result of the manufacturing process, tungsten is less than 100%
dense. In general, it gets denser as it's worked; e.g., pressed -
sintered - rolled - drawn.


Ah, thank you. You guessed what I'm interested in--tungsten at its most
dense state (or practically so--upwards of 18.4g·cm?3 at least.)
So, yeah--now I understand it's going to be over scrap price because it'll
be worked (in addition to markup of course.)


If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.

Why not just a cash sale?

Because I didn't know you could do that through eBay. If you mean a
straight cash sale direct, person-to-person, I could probably do that, but
there'd be more risk for me--what recourse would I have if I paid and never
got the item? But all this is moot if I can't meet your price. What price
range are we looking at?

"Todd Rich" wrote in message
...
Adam Corolla wrote:
Anyone have a solid piece of pure tungsten (98% pure or better) they
might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only.
I
don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.

Cool, that's just the sort of thing I'd like to have!!

Adam Corolla wrote:
Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

x-ray tubes use tungsten for the electrode/target. Nearly always round,
as the modern ones spin. I know that GE Medical Systems scraps out the
field returns, because a friend of mine runs the operation.
members.chello.nl/~h.dijkstra19/image/nago2.jpg
from this page:
http://members.chello.nl/~h.dijkstra19/page5.html

If the anode looks like something you'd be able to work with let me
know, I can see if they can sell the parts to individuals rather than
for scrap.

On 2007-10-19, Adam Corolla wrote:

"Ned Simmons" wrote in message
...
On Fri, 19 Oct 2007 13:37:15 -0500, "Adam Corolla"
wrote:

Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

I may be able to get you a piece for something above scrap value.


Fair enough.


As a result of the manufacturing process, tungsten is less than 100%
dense. In general, it gets denser as it's worked; e.g., pressed -
sintered - rolled - drawn.


Ah, thank you. You guessed what I'm interested in--tungsten at its most
dense state (or practically so--upwards of 18.4g·cm?3 at least.)
So, yeah--now I understand it's going to be over scrap price because it'll
be worked (in addition to markup of course.)


If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.

Why not just a cash sale?

Because I didn't know you could do that through eBay. If you mean a
straight cash sale direct, person-to-person, I could probably do that, but
there'd be more risk for me--what recourse would I have if I paid and never
got the item? But all this is moot if I can't meet your price. What price
range are we looking at?



I bought something from Ned and he was on the up-and-up.

i

"Todd Rich" wrote in message
...
Adam Corolla wrote:
Anyone have a solid piece of pure tungsten (98% pure or better) they
might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only.
I
don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.


P.S., I can wait weeks or months no problem. We can discuss the price when
it's available, but of course I can't commit to buy until we do agree on a
price.

Well, that's a bit less than I wanted. The minimum weight I'd be looking
for would be three pounds.

"Ignoramus5114" wrote in message
...
I have a small piece, maybe 3 oz.

i

On 2007-10-19, Adam Corolla wrote:
Anyone have a solid piece of pure tungsten (98% pure or better) they
might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only.
I
don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.

"Ignoramus5114" wrote in message
...
On 2007-10-19, Adam Corolla wrote:

"Ned Simmons" wrote in message
...
On Fri, 19 Oct 2007 13:37:15 -0500, "Adam Corolla"
wrote:

Anyone have a solid piece of pure tungsten (98% pure or better) they
might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

I may be able to get you a piece for something above scrap value.


Fair enough.


As a result of the manufacturing process, tungsten is less than 100%
dense. In general, it gets denser as it's worked; e.g., pressed -
sintered - rolled - drawn.


Ah, thank you. You guessed what I'm interested in--tungsten at its most
dense state (or practically so--upwards of 18.4g·cm?3 at least.)
So, yeah--now I understand it's going to be over scrap price because
it'll
be worked (in addition to markup of course.)


If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.

Why not just a cash sale?

Because I didn't know you could do that through eBay. If you mean a
straight cash sale direct, person-to-person, I could probably do that,
but
there'd be more risk for me--what recourse would I have if I paid and
never
got the item? But all this is moot if I can't meet your price. What
price
range are we looking at?



I bought something from Ned and he was on the up-and-up.

i

Well... I didn't mean to cast aspersions on Ned's honor--it's just that I'm
new here and don't know anyone yet. Thanks for the vouch, though.

Adam Corolla wrote:

If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.
Why not just a cash sale?
Because I didn't know you could do that through eBay. If you mean a
straight cash sale direct, person-to-person, I could probably do that,
but
there'd be more risk for me--what recourse would I have if I paid and
never
got the item? But all this is moot if I can't meet your price. What
price
range are we looking at?


I bought something from Ned and he was on the up-and-up.

i

Well... I didn't mean to cast aspersions on Ned's honor--it's just that I'm
new here and don't know anyone yet. Thanks for the vouch, though.

Adam, I've done many transactions via email with people I don't know
from forums like this. In most cases I've mailed money or the item
before I received anything from the other party. Call me naive, but I've
yet to get burnt.
You can get a pretty good idea of the character of a party by looking
up old posts. For that matter, Google the email address and see what
comes up.

Rex wrote:
... For that matter, Google the email address and see what
comes up.

Out of curiosity, I Googled my email address. There were 23 hits, all
of them copies of my NG posts, mostly RCM. These are web sites, with
copies of my posts in them! In fact, one site is nothing but copies of
RCM posts:
http://iron--steel.blogspot.com/

Why would anyone bother when the posts can be read directly? If not
from a news server, from Google:
http://groups.google.com/

Strange.

Bob

"Adam Corolla" wrote in message
...
Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only.
I don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I
will pay your listing fees.

See if there is a company near you that does TiN coating, they would have
what you want.

TIG welding electrodes with green tips used for AC welding aluminum and
magnesium are high quality pure tungsten.
Mcmaster stores have it in their stock.

"Todd Rich" wrote in message
...
| Adam Corolla wrote:
| Anyone have a solid piece of pure tungsten (98% pure or better) they
might
| want to sell? I'd like a piece weighing three to five pounds, but up to
| fifteen pounds is OK if the price is good enough.
|
| Notes: I don't want tungsten carbide or other alloy--pure tungsten
only. I
| don't want any porous pieces, they should be solid.
|
| If you're interested, we can arrange a private auction through eBay, I
will
| pay your listing fees.
|
| If it wasn't my only one, I've got a sintered 5# block from work. An
| unneeded engineering sample. I'll ask and see if they have any others,
| but I don't think they'll have one for a couple of weeks/months. It is
| weird how dense it is.
|
|
|

On Fri, 19 Oct 2007 16:07:44 -0500, "Adam Corolla"
wrote:


Well... I didn't mean to cast aspersions on Ned's honor--it's just that I'm
new here and don't know anyone yet. Thanks for the vouch, though.


And no offense taken. I've had just one bad experience with the folks
here - I think it's coming up on 8 years that one of the regulars here
has owed me a crummy $65.

I'll be at my customers plant on Monday
http://www.elmettechnologies.com/products/Tungsten/
and will try to get some answers about the value and availability of
scrap. Do you have any preference or requirements for the shape of the
lump?

--
Ned Simmons

Adam Corolla wrote:

"Todd Rich" wrote in message
(snip)
If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.


P.S., I can wait weeks or months no problem. We can discuss the price when
it's available, but of course I can't commit to buy until we do agree on a
price.

No guarantee I can get you one, but I'll try. Is it ok if it is several
smaller pieces, or machined somewhat? I'll have better luck getting scrap
or a part failed by inspection.

Are you the same Adam Corolla that had the TV show about remodeling your dad's
old house?

--
Dennis

So what are Tig pure tungsten sticks do for you ?
That might be a source.

Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Life; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Adam Corolla wrote:
"Ned Simmons" wrote in message
...
On Fri, 19 Oct 2007 13:37:15 -0500, "Adam Corolla"
wrote:

Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.
I may be able to get you a piece for something above scrap value.


Fair enough.


As a result of the manufacturing process, tungsten is less than 100%
dense. In general, it gets denser as it's worked; e.g., pressed -
sintered - rolled - drawn.


Ah, thank you. You guessed what I'm interested in--tungsten at its most
dense state (or practically so--upwards of 18.4g·cm?3 at least.)
So, yeah--now I understand it's going to be over scrap price because it'll
be worked (in addition to markup of course.)


If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.
Why not just a cash sale?

Because I didn't know you could do that through eBay. If you mean a
straight cash sale direct, person-to-person, I could probably do that, but
there'd be more risk for me--what recourse would I have if I paid and never
got the item? But all this is moot if I can't meet your price. What price
range are we looking at?



----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

P D Fritz wrote:
TIG welding electrodes with green tips used for AC welding aluminum and
magnesium are high quality pure tungsten.
Mcmaster stores have it in their stock.
They call that "EWP". They should have it in at least 1/8"
diameter, and 6" long.

Jon

Dave Hinz wrote:
Adam Corolla wrote:

Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.


x-ray tubes use tungsten for the electrode/target. Nearly always round,
as the modern ones spin. I know that GE Medical Systems scraps out the
field returns, because a friend of mine runs the operation.
They have a lot of tubes fail for various reasons. If you can
get a tube that has cracked, then there's no vacuum hazard to
worry about. Also, the dental X-rays have smaller, non-spinning
anodes. Many of these get dumped in the trash when they go bad.
Those probably are no more than a pound, though.

Jon

"Todd Rich" wrote in message
...
Adam Corolla wrote:
snip-----

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.

If you think tungsten's weird to handle, try gold, or even platinum. Both
are heavier, platinum by a considerable amount. It's about 10% heavier than
gold, which is about 12% heavier than tungsten. Both are very strange to
hold, and easily slip from your grip.

Harold

"Harold and Susan Vordos" wrote:

Both are very strange to
hold, and easily slip from your grip.

We seldom hold on any harder to things than we have to. If some one lifted
heavy materials every day their grip likely wouldn't slip but grabbing an
occasional block of wood or aluminum might get a tooth chipped.

I've noticed when holding something *expensive* that my grip is a lot
tighter and more tiring. I want to put it down as soon as I can.


Wes

"Wes" wrote in message
...
snip-----
I've noticed when holding something *expensive* that my grip is a lot
tighter and more tiring. I want to put it down as soon as I can.


You mean like when holding Aunt Martha's Tifffany compote? :-)

Harold

Bob Engelhardt wrote:

Why would anyone bother when the posts can be read directly? If not
from a news server, from Google:
http://groups.google.com/

Generally used by cybersquatters that buy a domain name on speculation and
hope to get someone to notice it and maybe offer to buy it.

Wes

On Oct 19, 4:27 pm, "Adam Corolla"
wrote:
"Ned Simmons" wrote in message

...

On Fri, 19 Oct 2007 13:37:15 -0500, "Adam Corolla"
wrote:

Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

I may be able to get you a piece for something above scrap value.

Fair enough.

As a result of the manufacturing process, tungsten is less than 100%
dense. In general, it gets denser as it's worked; e.g., pressed -
sintered - rolled - drawn.

Ah, thank you. You guessed what I'm interested in--tungsten at its most
dense state (or practically so--upwards of 18.4g·cm?3 at least.)
So, yeah--now I understand it's going to be over scrap price because it'll
be worked (in addition to markup of course.)

If you're interested, we can arrange a private auction through eBay, I
will
pay your listing fees.

Why not just a cash sale?

Because I didn't know you could do that through eBay. If you mean a
straight cash sale direct, person-to-person, I could probably do that, but
there'd be more risk for me--what recourse would I have if I paid and never
got the item? But all this is moot if I can't meet your price. What price
range are we looking at?


Just so you know, you could pay him through Paypal and they'll protect
you if the item isn't received. Also you can pay with a credit card
and the credit card itself offers protections.

On Fri, 19 Oct 2007 23:13:29 -0500, Jon Elson wrote:
Dave Hinz wrote:

x-ray tubes use tungsten for the electrode/target. Nearly always round,
as the modern ones spin. I know that GE Medical Systems scraps out the
field returns, because a friend of mine runs the operation.

They have a lot of tubes fail for various reasons. If you can
get a tube that has cracked, then there's no vacuum hazard to
worry about. Also, the dental X-rays have smaller, non-spinning
anodes. Many of these get dumped in the trash when they go bad.
Those probably are no more than a pound, though.

GE really does a remarkable job of salvage operations on returned parts
and so on. Some of it is cost-avoidance (recycle it at a loss so you
don't have to landfill it at a higher loss), some of it is profitable,
and some of it is just because that's the right thing to do. So, the
CRTs come apart - the copper yokes go into one bin, the Mu-metal in the
neck of the tube goes into another, the lead glass face of the tube goes
into another, the rest of the glass, the plastic, the steel chassis, and
all that gets put with more of the same. Any gold edge connectors on
circuit boards get sheared off and put into one bin, the rest of the
board into another. Amazing how fast those guys can take stuff apart.

And, yup, no radiation in an xray tube unless you're feeding it tens of
thousands of volts at the moment. I've got an older xray tube on my
desk; it's amazing that even within the company and division that made
it, so many people have no idea what it is or how it works.

On 2007-10-19, Bob Engelhardt wrote:
Rex wrote:
... For that matter, Google the email address and see what
comes up.

Out of curiosity, I Googled my email address. There were 23 hits, all
of them copies of my NG posts, mostly RCM. These are web sites, with
copies of my posts in them! In fact, one site is nothing but copies of
RCM posts:
http://i r o n--steel.blogspot.com/

Why would anyone bother when the posts can be read directly? If not
from a news server, from Google:
http://groups.google.com/

This is called "webspam", or "scraping". They profit from visitors
referred by search engines when the visotors click on the ads.

i

Harold and Susan Vordos wrote:

"Todd Rich" wrote in message
...
Adam Corolla wrote:
snip-----

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.

If you think tungsten's weird to handle, try gold, or even platinum. Both
are heavier, platinum by a considerable amount. It's about 10% heavier than
gold, which is about 12% heavier than tungsten. Both are very strange to
hold, and easily slip from your grip.

Harold

Admittedly, I'm pulling from wikipedia as a fast source, but it says
gold's density is 19.3, and tungsten's is 19.25.

http://en.wikipedia.org/wiki/Gold
http://en.wikipedia.org/wiki/Tungsten

And I have a platinum wedding ring, so I do have some experience with how
it feels. Though nowhere near as much as you do with your refining
experience.

Adam Corolla wrote:
Anyone have a solid piece of pure tungsten (98% pure or better) they might
want to sell? I'd like a piece weighing three to five pounds, but up to
fifteen pounds is OK if the price is good enough.

Notes: I don't want tungsten carbide or other alloy--pure tungsten only. I
don't want any porous pieces, they should be solid.

If you're interested, we can arrange a private auction through eBay, I will
pay your listing fees.





The Yard Aircraft Tools, sells a tungsten bucking bar. Not cheap, but
smaller and denser than any steel bucking bar.

Dunno if the block size would work for you, but you might look there.

Cheers
Trevor Jones

"Todd Rich" wrote in message
...
Harold and Susan Vordos wrote:

"Todd Rich" wrote in message
...
Adam Corolla wrote:
snip-----

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.

If you think tungsten's weird to handle, try gold, or even platinum.
Both
are heavier, platinum by a considerable amount. It's about 10% heavier
than
gold, which is about 12% heavier than tungsten. Both are very strange
to
hold, and easily slip from your grip.

Harold

Admittedly, I'm pulling from wikipedia as a fast source, but it says
gold's density is 19.3, and tungsten's is 19.25.

http://en.wikipedia.org/wiki/Gold
http://en.wikipedia.org/wiki/Tungsten

And I have a platinum wedding ring, so I do have some experience with how
it feels. Though nowhere near as much as you do with your refining
experience.

I stand corrected! I have long labored with the idea that tungsten's
specific gravity was in the vicinity of 17.1. A quick check of Machinery's
Handbook, page 1706, 15th edition, provides a range of 18.6/19.1, very
slightly less than the specific gravity of gold. I would attribute the
slight difference to the fact that it is not melted, although there may be
processes that fuses the material. Slight variations in density are
likely due to the degree of fusion. Dunno! :-)

What's funny is I've machined tungsten enough to have a general idea----yet
never made the connection with its density and that of gold.

Harold

On Sun, 21 Oct 2007 00:33:17 GMT, "Harold and Susan Vordos"
wrote:

Slight variations in density are
likely due to the degree of fusion. Dunno! :-)

That's more or less the situtation with the density. Fine tungsten
powder is pressed into bars. The bars are resistance heated (imagine a
rod the size of your thumb glowing at 4800F!) to sinter the powder.
The bars shrink and get denser as the tungsten crystallizes. Swaging,
rolling, and drawing increase the density and deform the crystals,
yielding the typical fibrous structure.

Lamp filaments run hot enough that the tungsten recrystallizes, which
is why a filament is more fragile once it's burned for a while.

--
Ned Simmons

Harold and Susan Vordos wrote:

"Todd Rich" wrote in message
(snip)
Admittedly, I'm pulling from wikipedia as a fast source, but it says
gold's density is 19.3, and tungsten's is 19.25.

http://en.wikipedia.org/wiki/Gold
http://en.wikipedia.org/wiki/Tungsten

And I have a platinum wedding ring, so I do have some experience with how
it feels. Though nowhere near as much as you do with your refining
experience.

I stand corrected! I have long labored with the idea that tungsten's
specific gravity was in the vicinity of 17.1. A quick check of Machinery's
Handbook, page 1706, 15th edition, provides a range of 18.6/19.1, very
slightly less than the specific gravity of gold. I would attribute the
slight difference to the fact that it is not melted, although there may be
processes that fuses the material. Slight variations in density are
likely due to the degree of fusion. Dunno! :-)

Makes sense to me. I've been reading up on the density of Osmium and
Iridium, and which one is denser depends on how they measure it.
http://en.wikipedia.org/wiki/Osmium

What's funny is I've machined tungsten enough to have a general idea----yet
never made the connection with its density and that of gold.

Harold

Well, I was thinking that if you were going to try and fool somebody with
'fake' gold, plating a bar of tungsten would be a much better choice than
lead. It would be too hard though. Maybe if you were dealing with a
large enough unit to make it worth it, give it a 1/16" thick surface coat.

Don't mind me...idle thoughts...

Dave Hinz wrote:
On Fri, 19 Oct 2007 23:13:29 -0500, Jon Elson wrote:

Dave Hinz wrote:


x-ray tubes use tungsten for the electrode/target. Nearly always round,
as the modern ones spin. I know that GE Medical Systems scraps out the
field returns, because a friend of mine runs the operation.


They have a lot of tubes fail for various reasons. If you can
get a tube that has cracked, then there's no vacuum hazard to
worry about. Also, the dental X-rays have smaller, non-spinning
anodes. Many of these get dumped in the trash when they go bad.
Those probably are no more than a pound, though.


GE really does a remarkable job of salvage operations on returned parts
and so on.
I have a friend who used to work on CAT scanners, now he is in
the MRI division at GE medical.

But, dental X ray machines are essentially just furniture to a
dentist. I doubt much of that gear is ever repaired, they just
aren't very expensive. I'm sure the hospital-grade xray suites
and certainly CAT scanner hardware is handled in an entirely
different manner.

Jon

Ned Simmons wrote:
On Sun, 21 Oct 2007 00:33:17 GMT, "Harold and Susan Vordos"
wrote:

Slight variations in density are

likely due to the degree of fusion. Dunno! :-)


That's more or less the situtation with the density. Fine tungsten
powder is pressed into bars. The bars are resistance heated (imagine a
rod the size of your thumb glowing at 4800F!) to sinter the powder.
The bars shrink and get denser as the tungsten crystallizes. Swaging,
rolling, and drawing increase the density and deform the crystals,
yielding the typical fibrous structure.

Lamp filaments run hot enough that the tungsten recrystallizes, which
is why a filament is more fragile once it's burned for a while.

This is SURE true! I make filaments for our vacuum leak checker
at work. I have a couple small spools of Tungsten wire (.007")
that comes annealed. It is a certainly stiffer than copper or
even mild steel wire, but not brittle at all. After a filament
has been in the machine, even for a few minutes, it is totally
impossible to do any work on it. Even the slightest touch, or
especially fiddling with the screws that mount it will cause it
to shatter.

Jon

snip-----

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.

If you think tungsten's weird to handle, try gold, or even platinum.
Both are heavier, platinum by a considerable amount. It's about 10%
heavier than gold, which is about 12% heavier than tungsten. Both are
very strange to hold, and easily slip from your grip.

Harold

A few years ago, I had to machine some spot-weld electrodes out of tungsten
for a local customer...office manager came out to the shop to get them, I
pointed to the parts on my toolbox, she picked them up and immediately
dropped them.

All 4 of them broke into at least several pieces, one SHATTERED! I still
find a shard or two on occasion.

Mike

"Ned Simmons" wrote in message
...
On Sun, 21 Oct 2007 00:33:17 GMT, "Harold and Susan Vordos"
wrote:

Slight variations in density are
likely due to the degree of fusion. Dunno! :-)

That's more or less the situtation with the density. Fine tungsten
powder is pressed into bars. The bars are resistance heated (imagine a
rod the size of your thumb glowing at 4800F!) to sinter the powder.
The bars shrink and get denser as the tungsten crystallizes. Swaging,
rolling, and drawing increase the density and deform the crystals,
yielding the typical fibrous structure.

Lamp filaments run hot enough that the tungsten recrystallizes, which
is why a filament is more fragile once it's burned for a while.

--
Ned Simmons

Thanks, Ned. Sort of confirms my hunch.

Harold

"The Davenport's" wrote in message
...
snip-----

If it wasn't my only one, I've got a sintered 5# block from work. An
unneeded engineering sample. I'll ask and see if they have any others,
but I don't think they'll have one for a couple of weeks/months. It is
weird how dense it is.

If you think tungsten's weird to handle, try gold, or even platinum. Both
are heavier, platinum by a considerable amount. It's about 10% heavier
than gold, which is about 12% heavier than tungsten. Both are very
strange to hold, and easily slip from your grip.

Harold

A few years ago, I had to machine some spot-weld electrodes out of
tungsten for a local customer...office manager came out to the shop to get
them, I pointed to the parts on my toolbox, she picked them up and
immediately dropped them.

Doesn't surprise me in the least. When I first started handling gold, I
often had it slip from my grip. You learn with exposure, but it's always
fun to hand someone their first experience.

Think of the conventional ingot of gold----400 troy ounces. About the size
of a modular masonry brick----and weighs a whopping 27.4285 pounds
avoirdupois.

Harold



All 4 of them broke into at least several pieces, one SHATTERED! I still
find a shard or two on occasion.

Mike

Trevor Jones wrote:

The Yard Aircraft Tools, sells a tungsten bucking bar. Not cheap, but
smaller and denser than any steel bucking bar.

Dunno if the block size would work for you, but you might look there.


http://www.yardstore.com/index.cfm?a...ls&ItemID=1738

PN: 74102
Tungsten Bucking Bar

* 2.87 lbs.

Try one of our "Vibration-Free" Tungsten Bucking Bars!

According to a recent University study, bucking bars made with tungsten are
much safer for the operator by reducing vibration. The density of tungsten
is the future of bucking bars available at The Yard today!

At The Yard all of our Tungsten Bucking Bars are made from 90+% tungsten.
All edges are deburred and working surfaces are polished for trouble-free
use. Your hands will thank you.

Wes

"Harold and Susan Vordos" wrote in message
et...

Think of the conventional ingot of gold----400 troy ounces. About the
size of a modular masonry brick----and weighs a whopping 27.4285 pounds
avoirdupois.

I have two 50-pound bricks of pure lead, which I inherited from my uncle,
who used them to cast lead sinkers and bullets. It's always entertaining to
ask one of my friends if he'd pick one up for me. d8-)

--
Ed Huntress