Old hard drives are good sources of strong rare earth magnets.

[Big Paul]

I have a couple of computer lobotomies at home. I will have to try this!!

[mddock58]

Here are pics of a common drive.





And these are the magnets removed, but still attached to their mountings.

[Peter C.]

When using magnets you need a piece of ferrous metal for the magnet to stick to, like a washer or something. When the magnet is stuck to the washer most of the magnetic field will be going through the washer so it will be almost no risk to credit cards unlike a loose magnet.

Peter

[Bob C]

I'm glad to see the warnings about credit cards and hotel keys. I've messed up hotel keys with the magnet from a name badge a couple times at conferences.

The danger is real. I'd never use magnets in a sporran.

[Big Paul]

My Buzz Kidder has a magnet clasp. I haven't had any problems..

[sjrapid]

...and these are the magnets removed, but still attached to their mountings.

Thanks mddock58, that's exactly the type of hint I was hoping for. I've disembowelled a number of drivers over the years, (I've got a stack of old platters in my office at work) but I've never gone after the magnets before.

Best regards

[mddock58]

Magnetic "information" CAN be changed by magnetic fields realigning the "data" on whatever it is on. the biggest danger to credit cards and such are the "Security" demagnitizers at stores ( so you don't walk off with a CD or DVD) which have a strong rapidly changing field.

Generally a magnet will not cause a problem with most items, but a magnet in a pocket or sporran freely moving about may cause data loss. It is not a simple "this will, and that won't". Caution in the size and strength of a magnet should always be considered.

Using them to keep a kilt pin on should not cause any worry, unless there is a metal plate in your leg!