case hardened

Adjective

(metallurgy) Metal that is harder at its surface, due to a case hardening process.

Japanese Meaning

表面が硬化処理によって硬くなった金属

The case hardened shaft continued to perform reliably despite years of heavy industrial use.

表面硬化処理が施されたその軸は、何年もの過酷な工業使用にもかかわらず安定して機能し続けた。

Sense（1）

(metallurgy) Metal that is harder at its surface, due to a case hardening process.

more case hardened

（ comparative ）

most case hardened

（ superlative ）