Hodlinox can be purchased at hodlinox.com. Claims to be fire proof, water proof, corrosion resistant and unaffected by various acids: this 316 stainless steel plate is virtually indestructible.
Setup was straightforward; the one annoyance I had was that the back plate is not a flat surface due to the threading for the screw, thus it was harder to keep secure when stamping letters.
Heat Stress Test
It was slightly challenging to reopen the Hodlinox because the plates bowed slightly (about 1 mm) such that the clamp on the bottom plate was holding the top plate in place. Just had to pry the pieces apart a bit and hammer the top plate off to the side.
We can see that the etched words are still legible, though faint, while the stamped words are quite easy to read. Note that I didn’t fill the whole device with words in order to minimize my time spent doing so.
Corrosion Stress Test
Doesn’t appear to have become any less legible in comparison to the heat test.
Crush Stress Test
Performed as expected given that it’s just two sheets of steel; no data loss.