The Tungsten M-1—How Ukraine’s Tanks Will Differ From America’s

There’s a good reason it might take months—even the better part of a year—for Ukraine to get those first 31 M-1A2 Abrams tanks from the United States.

Vehicle-maker General Dynamics Land Systems has to remove the uranium from the tanks then swap in tungsten. Both metals can be problematic.

It takes six months for GDLS to build an M-1A2 at the government-owned tank factory in Lima, Ohio. The firm manufactures just three “new” tanks a week, using as the basis of each one of the thousands of surplus M-1s sitting around at U.S. Army arsenals. All have a depleted-uranium mesh in their armor mix.

Depleted uranium is a byproduct of the nuclear industry. In the United States, it falls under the purview of the U.S. Department of Energy—and is subject to DOE regulations that bar its export.

Not everyone agrees the export-ban is necessary. As far back as 1986, the U.S. General Accounting Office—now the Government Accountability Office—questioned the regulation. “DOE should be able to develop more objective criteria that will allow flexibility while better meeting established nonproliferation goals,” the GAO asserted.

Unless and until the rules change, an M-1 has to lose its depleted uranium, and get something to replace it, before the U.S. government will sell or donate the tank abroad.

That something is tungsten. A very hard metal that’s the key to American tank exports. When the United States sells M-1s to its allies—Iraq, Saudi Arabia, Australia, Taiwan and Poland all are recent customers—it pays GDLS, and only GDLS, to stuff tungsten into the steel “pockets” on the front of the M-1’s turret and also, on some models, on the front of the hull.

The work takes time. It doesn’t help that General Dynamics Land Systems has a monopoly on the trade. “GDLS is currently the only known contractor with the necessary secure armor facilities and necessary production equipment capable of supporting the installation of classified armor into the Abrams main battle tank,” the U.S. government noted in a recent justification of a sole-source contract to the company.

It’s not clear that the tungsten-armored M-1s are significantly more vulnerable to enemy fire than the uranium-armored M-1s are.

Both metals are very dense, after all. Steel has a density of around eight grams per cubic centimeter. Uranium and tungsten both tip the scale at a hefty 19 grams per cubic centimeter.

Which doesn’t mean you’d cover a whole tank in either of the silver-colored metals. For starters, both metals are hard to come by. Depleted uranium is a nuclear byproduct. Tungsten meanwhile comes from a vanishingly small number of mines, many of which are in China.

Also, depleted uranium tends to combust under certain conditions—and it’s just radioactive and toxic enough that it represents a safety risk when it burns.

Tungsten for its part is dense but brittle. It tends to shatter on impact. When the U.S. Defense Department investigated tungsten outer armor back in 1960, it came away disappointed. “The use of a hard [tungsten] facing does not appear worthwhile for improvement of the ballistic performance of armor,” the testers reported.

It’s not for no reason that armor-makers tend to fold depleted uranium and tungsten into cake-like armor mixes that also include ceramics and steel—and tend to have the steel on the outside. The Ukrainian M-1s, like all non-American M-1s, will feature this tungsten-on-the-inside armor blend.

They’ll have company. At least some of the German-made Leopard 2 tanks that Germany, Poland, Norway, Canada and other countries have pledged to Ukraine also have tungsten in their armor.