noun
gold and iron; firmness; adamancy
Literary or figurative term for something extremely solid and unyielding, like gold and iron. Often used metaphorically for unwavering resolve or unbreakable bonds.
二人の友情は金鉄の絆だ。
Their friendship is a bond of gold and iron.
彼の決意は金鉄のように固い。
His determination is as firm as gold and iron.