This is another unique device because it’s not a commercial product. SAFU Ninja is a “recipe” for building an affordable DIY backup with materials from any hardware store. Why would you want to do this? Privacy, for one - if you have commercial products shipped to your house in your name, that information might be leaked in the future…

SAFU Ninja doesn’t appear to make any claims about its durability. It’s comprised of just 3 simple parts:

  • M6 or 1/4" hex Stainless Steel bolt 1-2 inches long
  • M6 or 1/4" Stainless Steel Acorn Cap Nut
  • 1/4" x 1" or M6 Stainless Steel Fender Washers


Due to the shape and size of the washers, it’s a huge pain to stamp letters into them. Also, as is the case with any device composed of loose tiles that could potentially fall out of order, there’s the issue of numbering the tiles. If I were to do this for real, I’d stamp one word per washer side, along with the number of the word.

Heat Stress Test

No data loss.

Corrosion Stress Test

No effects.

Crush Stress Test

Performed better than I expected; I thought the bolt would shear off and the tiles would go flying. Clearly that will happen at some point, but it will take more than 20 tons of force to do so. Perhaps it would have performed a bit better if I had a few more washers in there to prevent there being any wiggle room.

While there was no data loss in this test, I’m less confident in devices with tiles that could become loose and thus lost.