Crypto Keys can be purchased at crypto-keys.com. It doesn’t appear to make any claims about its durability.

Setup

Pretty simple - a dozen pieces of steel, but from experience running these tests simple is good. Major bonus points that they ship with a 3D printed stamp holder. FYI it’s not advisable to try to stamp the pieces while they’re still on the key ring; they need to be completely flat on the stamping surface.

Heat Stress Test

No data loss.

Corrosion Stress Test

No data loss.

Crush Stress Test

It was no surprise that the pieces bent under pressure - you can actually bend them by hand if you try hard enough. However, the steel pieces would need to be completely torn apart in order to cause data loss.