Grant Hardy argues that the use of "brass" and "steel" are anachronistic to both the Old and New World in the 6th c. BCE, and that iron is unattested in the New World before Columbus.
Grant Hardy, The Annotated Book of Mormon (Oxford: Oxford University Press, 2023), 101
15: Nephi’s knowledge of metallurgy would have been unusual. Brass and steel are anachronistic for the 6th c. BCE; the use of the two metals, along with iron, is unattested in the New World before Columbus.