"坚如钢铁"这个短语可以用"as tough as steel"来表达。这个短语源自于"钢铁"这种金属的坚韧性。
例句：
She has a will of steel and never gives up no matter how difficult the situation is. (她有钢铁般的意志，无论遇到多么困难的情况也从不放弃。)
He has a heart of steel and never shows any emotion. (他心如钢铁，从不表现出任何情绪。)
The steel beam can support the weight of the building. (钢梁能支撑起整栋建筑的重量。)