Thanos is undoubtedly the greatest villain in the history of the Marvel Cinematic Universe. And every great villain needs an equally great weapon. Aside from the Infinity Gauntlet, the weapon that is most associated with Thanos is his double-edged sword. The exact weapon the Mad Titan used to destroy Captain America’s shield in Avengers Endgame. Considering Cap’s shield is made from Vibranium, the strongest metal on Earth, Thanos’ sword must be made of something stronger. Something other-worldly.
What is Thanos Double-Edged Sword made of?
Thanos sword is very likely made of Uru, one of the strongest metals in the Universe. The same substance that was used by Eitri to make Thor’s weapons on Nidavellir – Mjolnir and Stormbreaker.

Uru is a metal ore found only on the first moon that came into existence. It is incredibly durable. It’s main property is that it has the ability to easily absorb and hold magic. Uru is highly difficult to forge and can only be melted under extreme circumstances, such as in the heart of a star.
When speaking with Comicbook about what Thanos sword is made of, here is what co-Director Joe Russo had to say:
Clearly Thanos is a thousand-year-old character who has fought everyone in the universe and is the greatest: He’s the Genghis Khan of the universe, so he would have the greatest weapon.
He knows of Eitri, he’s been to Eitri to have his glove created. Did he have them create his blade as well? Potentially. But it’s interesting that it could destroy the shield.
Joe Russo
Without confirming it, the Director is certainly strongly hinting that the sword is made of Uru. Perhaps Marvel have plans to reveal the mystery down the line at some point. Maybe in a future episode of the What If series? For now, fans will just have to assume based on the best evidence that is available.
As always, thanks for reading.