
Tungsten: The Perfect Metal for Bullets and Missiles (2014) - jpelecanos
http://www.bbc.com/news/magazine-28263683
======
trhway
>Because, as the people of Kuwait discovered after first Gulf War, depleted
uranium leaves a potentially deadly dust behind after it burns. It sounds
bizarre but, in the world of warfare, tungsten is the eco-friendly
alternative.

i knew it is bad, just googled and according to some sources it is really bad,
especially when it comes to birth defects :
[http://www.huffingtonpost.com/craig-considine/us-depleted-
ur...](http://www.huffingtonpost.com/craig-considine/us-depleted-uranium-as-
ma_b_3812888.html)

It is not necessary radioactivity that makes DU that bad, it is its toxicity
that does it. Unfortunately, DU is still better for armor penetration :
[https://www.theguardian.com/world/2000/may/18/armstrade.koso...](https://www.theguardian.com/world/2000/may/18/armstrade.kosovo)

"Armour penetration is increased by concentrating the force of a shell into as
small an area as possible, so the projectiles tend to look like giant darts. [
... ] The other metal used for anti-tank rounds is tungsten, which is also
very hard and dense. When a tungsten rod strikes armour, it deforms and
mushrooms, making it progressively blunter. Uranium is "pyrophoric": at the
point of impact it burns away into vapour, so the projectile stays sharp. "

~~~
InclinedPlane
For penetrators you want density, hardness, and other penetration aiding
properties. Tungsten is very dense, but as you point out it blunts when
hitting a target, reducing its effectiveness (but if you have enough it'll
still work).

The guardian article you linked is a little bit off on the properties of
Uranium. Uranium is self sharpening (which means that when it slams into a
target it fragments splinters off, leaving behind a sharp point). Uranium is
also pyrophoric, which doesn't mean that it burns away pieces into vapor,
rather it means that when it scrapes along as it's penetrating through metal
it throws off sparks, just as flint and steel does. Additionally, Uranium is
more flammable than Tunsten. This means that a long rod Uranium penetrator can
punch through thicker armor than Tungsten and it spits out a rain of sparks
and splinters as a _burning_ hypervelocity rod comes through the other side of
the armor. This leads to a very bad day for the target.

However, because of that pyrophoricity and that burning the result of using
lots of DU shells on hardened armored targets is a lot of DU dust and vapor.
Because Uranium is a toxic heavy metal this can have disastrous health
effects.

~~~
the_af
> _However, because of that pyrophoricity and that burning the result of using
> lots of DU shells on hardened armored targets is a lot of DU dust and vapor.
> Because Uranium is a toxic heavy metal this can have disastrous health
> effects._

Well, I imagine being hit by a tank round has so profoundly disastrous health
effects anyway, the metal toxicity doesn't matter much!

(Yes, I know you probably meant adverse health effects for the people who
wander into the area _after the crew is killed_ , much like it happens with
nukes, but still. The considerations are bizarre, like the article said)

~~~
petre
> Well, I imagine being hit by a tank round has so profoundly disastrous
> health effects anyway, the metal toxicity doesn't matter much!

It's also toxic for the people firing the rounds because blowing up a
cartrigde will also evaporate some trace amount of the bullet.

------
rmm
There are large tungsten deposits outside of China. The issue is, China has
such a monopoly it controls the price.

I have been apart of at least three Tungsten Mine pre-feasibility studies. All
they need to do is ramp up production, and the price falls to a point where
NPV of your tungsten project falls to zero.

~~~
swalsh
Prices aside, you probably also don't want to introduce a dependency on china
in your weapons supply chain. This I believe was also the primary reason for
the GM bailout.

~~~
maxerickson
What does GM make that is important to military readiness?

I can think of the Hummer, but that wasn't GM
[https://en.wikipedia.org/wiki/AM_General](https://en.wikipedia.org/wiki/AM_General)
.

~~~
rz2k
Possibly the idea that a large number of subcontractors and suppliers would
also have gone out of business.

I think it would be difficult to determine which rationales were sufficient to
get enough votes for the bailout to pass, but the cost of creating a supply
from scratch after a period of zero demand from GM might have been far more
expensive to the aggregate economy than the bailout was. Therefore the cost
was judged 'worth it' in spite of the implicit reward to GM for decades of
mismanagement.

~~~
maxerickson
The bailout involved completely wiping out the equity of GM. The GM that
exists now is a different company:

[https://en.wikipedia.org/wiki/Motors_Liquidation_Company](https://en.wikipedia.org/wiki/Motors_Liquidation_Company)

The bailout can still have been a sweetheart deal for the creditors of the
company, but it didn't do the old GM any good.

I tend to think the motivation of the bailout was to reduce disruption in the
job market, I don't think there would have been much more than a short term
disruption in the OEM business.

------
zimpenfish
TAOFLEDERMAUS have done a few videos on Tungsten rounds / strength.

Tungsten carbide slugs:
[https://www.youtube.com/watch?v=UDWD4VM-31E](https://www.youtube.com/watch?v=UDWD4VM-31E)

Shooting a tungsten cube:
[https://www.youtube.com/watch?v=n5kEj5ijChc](https://www.youtube.com/watch?v=n5kEj5ijChc)

etc.etc.

~~~
mcguire
Taofledermaus and AvE? I'll be off in the weeds for a while.

------
hwillis
>Tungsten's only rival for this kind of application is the radioactive element
uranium. Depleted uranium is (almost) as dense as tungsten and has an added
advantage - from a military perspective - that it burns at the extreme
temperatures generated as you punch your way through steel tank armour.

It's also self-sharpening (ie rather than smooshing like plastic on contact,
parts break off and leave a sharp edge behind like flint), and because it's
effectively subsidized by power generation and the nuclear program it's
extremely cheap compared to Tungsten. Tungsten alloys are tougher[1]
(actually, some of the toughest materials period) but penetration depends
heavily on the armor type.

Hell, tungsten is toxic too and the military's biggest motivation is probably
just as a really effective PR move. Uranium is definitely worse though, and
I'm glad the US doesn't use it in munitions much. Uranium forms oxides that
are very bioavailable (and even absorbed as gas through the lungs), and are
really bad for you and even worse if you get pregnant.

[1]:
[http://www.cam.ac.uk/sites/www.cam.ac.uk/files/news/research...](http://www.cam.ac.uk/sites/www.cam.ac.uk/files/news/research/news/110908-granta-
design-chart.jpg)

~~~
3pt14159
Just PR? Really?

Isn't drag essentially quadratic to speed? Isn't needed input energy also
quadratic to speed, while momentum is linear to both mass and speed? Hardness
aside don't you have much harder hitting bullets with these heavy elements?

~~~
hwillis
The density of tungsten is 1.04% higher than Uranium, and drag is compensated
for by making the penetrator slightly longer rather than wider.

> Hardness aside don't you have much harder hitting bullets with these heavy
> elements?

Maybe I'm tired but I can't parse this question.

------
Steve44
If you're interested then have a read about the development of Chobham and
Dorchester armour. There is very little detail out there but fascinating to
see how some of the military kit is made and what it can stand up to.

------
logotype
Funny to see this article here now. For the last few weeks I've been geeking
out on exotic materials, and especially Tungsten Carbide. I even went so far
to buy a polished Cobalt binded TC 70mm sphere from China. It's virtually
indestructible and very few materials such as diamond can scratch it.

~~~
rimliu
My wedding band is made of tungsten carbide. I thought about is as a bit
different (neither my wife nor I are fond of gold) but certainly not exotic.

~~~
Steve44
That's an unusual material for a ring, I just hope you don't get into the
situation where it needs to be cut off. That would put me off using such a
hard metal for rings and jewellery chains.

~~~
ckluis
First responders actually have a device which cracks tungsten rings (I have
one), but they are easier “crack” than cut.

[https://www.youtube.com/watch?v=poM423pewRE](https://www.youtube.com/watch?v=poM423pewRE)
\- “the home way”

[https://www.loupe-
magnifier.com/tungsten_finger_ring_removal...](https://www.loupe-
magnifier.com/tungsten_finger_ring_removal_tool.htm) \- “the professional way"

~~~
Steve44
Interesting thank you. I'm still not sure I'd go for one but it's not as bad
as I'd thought providing they know what they are dealing with.

------
dogma1138
It's really not the perfect metal for neither bullets or missiles.

Tungsten will strip out any barrel, even normal copper jacketed bullets can
strip a barrel after a few 1000's of rounds.

Some calibers are prone to stripping more than others which is why some high
end rounds will be covered by a polymer coating that adds lubricity and
protects the barrel (it also has the benefit of dampening some inconsistencies
in the barrel itself which can improve precision).

Tungsten given enough velocity will go through pretty much anything, this
isn't something you want with bullets both because you usually do not want
bullets to go beyond their targets and that a bullet needs to be able to dump
it's energy into the body to be effective.

Small caliber through and throughs leave much less tissue damage unless
hitting a vital organ and even then a larger, slower round that deforms would
transfer more energy to the target.

The velocity of the bullet has a hard limit and that is the energy that is
stored in the chemical propellant.

As for missiles tungsten is heavy as fuck, it's denser than Uranium and Lead
you want your missiles to have as long of a range as possible, be as fast as
possible (to be harder to intercept) for that you need them to be as light as
possible. If you can make your missiles take on more weight and you've already
achieved the desired range and velocity then you better off just putting more
stuff that goes boom than an inert metal that does nothing.

Tungsten, just like high carbon steel and depleted uranium is useful for only
one thing and that is penetrating armor, in those cases you would optimize
your penetrator for that task meaning you'll be using a small narrow profile
(basically a dart, or well a flechette) which moves really fast and can
compromise heavy armor.

The only real use for tungsten in traditional projectiles it to defeat
composite reactive armor that would make shaped charges and other traditional
anti armor munitions less or completely in effective.

Even in those cases the tungsten penetrator is more often used to either
disable the vehicle by destroying it's engine block, turret controls,
suspension and tracks or by compromising the main body armor and then
finishing it off with a explosive anti armor around that would also cause crew
casualties (in a war of attrition killing the tank crew is often more
important than destroying the tank).

It's also important to note that tungsten penetrators are often not made out
of pure tungsten since it blunts (relatively) easily, so carbides and other
really hard materials would be used to make it even more effective.

Besides that Tungsten might be useful for gravity penetrators basically
"bunker busters" although in that case DU and lead might be just as potent
unless you are limited by the size of the bomb itself.

Lastly the only other real use of Tungsten is in DIME warheads, these warheads
employ inert metal powder as the force delivery mechanism, they fill their
effective area with micro-shrapnel that pretty much would tear and liquify all
tissue within it's blast radius but due to the high density of the metal and
the limited explosive charge have a very small blast radius for intended
lethal zone reducing direct collateral damage to zero.

~~~
arprocter
>Tungsten will strip out any barrel

I'd guess this can be prevented by using a tungsten core surrounded by a
copper jacket, or an exposed tip as in m855a1

Strange that the article didn't mention who was first to field tungsten AP
ammunition - it was the Luftwaffe

Edit: I didn't mean to imply m855a1 contains tungsten, rather that a similar
design could prevent excessive barrel wear

~~~
dogma1138
IIRC the A1 actually ditched the tungsten core, it's a "lead free" round not
AP, the M855 was supposed to be an "environmental friendly" round the tungsten
isn't a penetrator really it's some sort of composite matrix but after studies
showed that Tungsten is just as bad an even worse than lead as far as the
environment goes they've redesigned the round.

The M855A1 is also lighter than the M855 so if my memory serves me correctly
they've switched to a mild steel core.

The M955 does use a tungsten carbide penetrator and is classified as an AP
round but the usual "green tip" (or well just "green" ammo now since the A1
doesn't have a tip color) ammo that is in use uses steel penetrators for the
most part.

~~~
hoytech
Interesting. I had assumed tungsten was environmentally friendly since it is
permitted for waterfowl hunting:

[http://www.cabelas.com/product/Non-Toxic-Shot-Buyers-
Guide/5...](http://www.cabelas.com/product/Non-Toxic-Shot-Buyers-
Guide/532009.uts)

------
HankB99
Interesting. In the SciFi series (and books) The Expanse the rail gun
projectiles were tungsten. I thought it was just due to the heat resistance of
tungsten but it might have been chosen by the authors for the additional
property of density. I wonder if the electrical properties make it suitable
for the mechanisms used for rail gun propulsion.

~~~
hwillis
It's almost always chosen for density in scifi- most early railguns used
tungsten because the density means you can have a very small cross section per
unit mass, meaning low wind resistance which is important at super and
hypervelocity. Of course it's irrelevant in space, but it carried over to sci-
fi anyway.

------
Animats
Tungsten, the song.[1]

 _Tungsten, wolfram, makes the steel so hard._

 _It goes thru the side of an army tank as tho it were a paper card._

 _If you want to rule the world, never mind wrong or right,_

 _All you got to have is tungsten wolframite._

[1]
[https://www.youtube.com/watch?v=qbhP6b_2IUE](https://www.youtube.com/watch?v=qbhP6b_2IUE)

~~~
daef
this video is not available

~~~
mirimir
[https://www.vagalume.com.br/malvina-
reynolds/tungsten.html](https://www.vagalume.com.br/malvina-
reynolds/tungsten.html)

