Mm... 2mm sounds more like the likely ballpark. After I killed two (*TWO*) IBM (IoMega) 1GB Microdrives by dropping them 3" (three inches) on to a wooden tabletop on separate occasions, they finally modified the design to incorporate inset rubbery blocks in the corners of the case.

I imagine the rubber might deform as much as 1mm or so on impact, which would absorb a lot of G force.

But I've gone solid-state for embedded drives now. No looking back.

Cheers