I was installing a new hard drive into my computer yesterday and thought you'd enjoy this bit of kit; Inside the modern hard disk are between 1 and 3 metal platters that are what your information is written on to. With the removal of a dozen or so torx screws you can pry off the top cover of a dead hard drive, remove the armature, and free these plates from their spindle. What you have now are mirror finished metal disks that have a very convenient sighting hole in the center. The entire process takes about 10 minutes and it also allows you to pull of the circuit board so that the casing material and top plate can just be tossed into the recycling bin. Note; don't open a working disk, that's just dumb.