[thesuitonym]

If your threat profile really includes the possibility of getting hit by a wrench, you can devise a means of destroying the key quickly.

[bombcar]

Also if the wrench is a consideration, you really need to consider at what point you die rather than reveal.

And note that you may die even if you want to reveal; especially if you've setup a system that prevents you from revealing (two person keys, etc).

[aYsY4dDQ2NrcNzA]

My YubiKey seems pretty rugged, which is why I feel okay carrying it on my (physical) keychain.