What are hard disk platters made from?

Avoriaz

I don't have a problem, I just want to satisfy my curiosity.

The Maxtor Quickview 40gb hard disk in my Sky+ box failed a while ago. It was over four years old and the warranty had unfortunately expired about six months previously.

Out of curiosity I took it apart last night, expecting to find a platter or platters coated in brown material like tape, floppy drives etc used to be.

Instead I found one very shiny metal disk with a mirror finish.

There was only one read/write head so presumably only one side of the platter is used, although both sides appear to be identical.

What are these disks made from or coated with and are all hard disks like this?

amcluesent

Aluminium disks covered with a cobalt alloy

Avoriaz

Thanks.

I have now found a few interesting web sites that go into it in detail.

http://www.google.co.uk/search?hl=en&as_q=hard+disk+platter&as_epq=&as_oq=&as_eq=&num=10&lr=&as_filetype=&ft=i&as_sitesearch=&as_qdr=all&as_rights=&as_occt=any&cr=&as_nlo=&as_nhi=&safe=images

fwor

Apparently unlike yours, some are made with glass disks, again coated with a complex outer layer:

http://en.wikipedia.org/wiki/Hard_disk_platter

I've got a couple here from an old Seagate drive, and they are exactly as you describe.

Joe_Bloggs

If you can collect enough of them you can make one of these. There is scope for making a bell/sounding apparatus out of the disk platter. The magnets that facilitate the rapid read/write head translations are hazardous for those with heart pacemakers.
J_B.

Avoriaz

Joe_Bloggs wrote: »

If you can collect enough of them you can make one of these. There is scope for making a bell/sounding apparatus out of the disk platter. The magnets that facilitate the rapid read/write head translations are hazardous for those with heart pacemakers.
J_B.

The magnet from the disk I took apart is very powerful for its size.

I'm not surprised they might affect pacemakers.