Hush Steel is one of the many special metals in Isekai and is by far one of the most useful in terms of forging. Referred to as one of the Noble Metals, the dull greys of this metal make it look identical to Iron.
Look at that magnificent battleship and its state-of-the-art technologies! This is the first purpose-built steam battleship in history, and also the first with a screw propeller. That will show those English who is the boss!