Are there any rules for adamantine as a material outside weapons/armor?

I've obviously found the weapon and armor rules for the material.  But what if I want to have a wall of it?  Or something else made of it?

I can derive its as heavy as steel.  But is there anything about material strength?  I know in previous editions it could not be deformed or bent by mundane means -- is that still true in 5e/2024?

Not really, no. There's a very brief description of it in the 5.5e Dungeon Master's Guide Lore Glossary, but I don't believe there's any specific rules for using it outside of armor and weapons in the current edition.

I don't think the idea that it has the same weight as steel is really supported by anything in the rules other than the fact that it's used in armor and weapons.

There is a collection of setting-specific Forgotten Realms lore about adamantine from past editions here.

Not sure if it helps, but there's also a table for Object Armor Class that lists iron, steel, and adamantine:

Sadly, no.  I was hoping for something that hinted at any structural properties.  eg, how rigid/flexible is it.  (The prior edition 'can not be deformed or bent by mundane means' was a useful thing to know.  Also kinda insane).