What are hard drive platters made of?

I took apart a hard drive to start makine AP Digital Light's hard drive clock, but before I cut the slot for the light to come through, I'd like to know what the platters are made of, just in case they have something harmful in them.


blkhawk4 years ago
The platters are made of aluminum and they are coated with a film of magnetic material (I believe that is some type of oxide). It should not be harmful but do take precautions not to aspire any fine dust. Keep us posted about your progress.
AndyGadget4 years ago
You're talking about 3.5" drives here, but just a word of warning if anyone's thinking of playing with 2.5" laptop drives. 
I took one of these apart once and bent the platter with my fingers to find what sort of 'metal' it was made of.  It was actually made of metal coated glass and it shattered and showered me with a billion razor-sharp shards.  Apart from a few minor cuts to my fingers I was OK, but I'd have probably lost my sight if I wasn't wearing reading glasses.
ihagy AndyGadget11 months ago

mine just shattered. thats why im here.

MichaelM1 ihagy6 months ago

Hahaha! That's why I'm here

qwertyboy (author)  AndyGadget4 years ago
Wow, I had no idea that they were glass. I would have thought they were the same material as a regular hard drive.
I don't know if all the 2.5" ones are glass, but I certainly found out the hard way that the one I was bending was.
boxfreind2 years ago
Also, I am not aware of any toxic materials inside a hard least nothing that would pose any type of health risk. I have taken hundreds of these apart within the last 15 years without any sort of protection and I am just fine.
boxfreind2 years ago
From what I understand, they used to be made of some sort of metal coated with a magnetic layer of nikel. Now days they are made of what is basically a type of glass or ceramic (depends on manufacturer) also coated in Nikel.
Salsands2 years ago
I'll tell you one thing: putting a bare 2.5 hd platter on the surface of an iPad does not make the iPad very happy.
jheinzen3 years ago
The plates themselves are constructed with a combination of metal, glass and ceramics. They are also covered in an extra layer of thin carbon for protection, followed by a layer of magnetic material which is what is manipulated to signify data.
orksecurity4 years ago
GIFY. Typing your question directly into a websearch engine yields Wikipedia's entry as its first hit, which does answer your question.