Usually 角材 is translated as "squared lumber" or "2-by-4" (never mind the actual dimensions), but that wouldn't work here since the definition Hibiki gives include stone (角材 technically also includes stone blocks, and maybe even other "squared" construction material, but this use is far less common such that some dictionaries exclude them altogether).

So I whacked both "dimensional lumber" and "dimension stone" together to compromise. A quick check also reveals that "dimension material" is a also a (somewhat rare) term used in the construction industry (but in more formal technical contexts, like research papers, published guidelines/rulings and textbooks).

Oh hey, there's a better term that is more commonly used. Also has a built-in wood bias as well.

I was expecting a pile-driver.

Hibiki cosplaying as the Mayor

Mayor Mike approves