In article 18f61e5e-4d9d-47df-a0df-02e6e1ff9c23
@j28g2000vbp.googlegroups.com, says...

On May 25, 11:30*am, Ignoramus23924 ignoramus23...@NOSPAM.
23924.invalid wrote:
I have a little industrial demagnetizer from a grinding shop. Can this
thing erase contents of hard drives securely? Or the magnetic field is
not string enough? I have a pile of old HDs awaiting destruction.

THe alternative is my press, which is more of a PITA.

Thanks

Drill a hole through the critter and shatter the platters.

If I had a bunch I'd make up a quick set of 1/4 or 1/8 inch punches
for my dake arbor press, set up like a spot welder- hold the platter
between the punches, pull the lever until you hear "crunch", repeat.

Of course you can never have enough head control magnets...

Quick and dirty way, open the drive up, toss in a handful of hundred
mesh silicon carbide and a teaspoon of nitric acid, close it up, and run
it until parts stop rattling around inside it.

Not as good as grinding the platters to dust, mixing with thermite,
burning, and scattering the ashes, but it's less effort.