The key says: "If I rest, I rust. "(

钥匙说：“如果我休息了，我就生锈了。”

youdao

The significant inscription found on an old key---“If I rest, I rust”---would be an excellent motto for those who are afflicted with the slightest bit of idleness.

在一把旧钥匙上发现了一则意义深远的铭文——如果我休息，我就会生锈。 对于那些懒散而烦恼的人来说，这将是至理名言。

youdao

The significant inscription found on an old key-" if I rest, I rust"-would be an excellent motto for those who are afflicted with the slightest taint of idleness.

对于那引起为懒散而苦恼的人而言，这无疑是一则最好的箴言。

youdao

There are ghosts of dozens of conversations in the hallways, stories I remember about buying new plows that now rust in the barnyard and ruined crops from the same vines that we are now harvesting.

NPR: Natural Links in a Long Chain of Being

In my case, because titanium does not rust or fatigue appreciably, its useful life is until I die.

FORBES: Why You Need a Custom Road Bike