A word in notes written between the 1st and 2nd edition of The Lord of the Rings, glossed “hard-iron = iron hard” as a combination of torna “hard” and anga “iron” (PE17/56). It seems it could be used as both a noun and an adjective, though it is possible Tolkien intended it to be only adjectival like the nearby vanimelda “elven-fair”.
Neo-Quenya: This word might also be used to mean “steel” as a replacement for the early word ᴱQ. akse, though I personally retain ᴺQ. axë “steel” for purposes of Neo-Quenya; see that entry for discussion.
tornanga adj. "iron hard" (the order of the elements is the opposite in Quenya). (PE17:56)