[tregg]

The 2.5", 3.5" and 5.25" Are these the measurements of the acutal disk? Is there a way to get this from the outside case dimensions?

[smax013]

tregg, on 10 August 2011 - 12:14 PM, said:

The 2.5", 3.5" and 5.25" Are these the measurements of the acutal disk? Is there a way to get this from the outside case dimensions?

As I understand it, the 8", 5.25" and 3.5" "form factors" came about as descriptions for the size of a floppy drive that would support an 8", 5.25", or 3.5" floppy disk, respectively. In other words, the 3.5" "form factor" was shorthand for the size/space taken up by a 3.5" floppy disk drive...since the floppy disk itself was 3.5" wide, that meant the drive had to be a little wider. Even though there are no 2.5" or 1.8" floppy disks (at least that I am aware of), they continued the "pattern" with those smaller form factors.

The end result is that you will not find a 5.25" dimension on a 5.25" drive. It will be a little bit bigger than that 5.25" dimension. Think of it as a "nominal" dimension...kind of like how a 2x4 is not actually 2"x4".

The three that you listed are the commonly used sizes. The easy way to thing of them is 5.25" is for desktop optical disc drives, 3.5" is for desktop hard drives, and 2.5" is for laptop hard drives (although you can put them in a desktop as well...the point is that virtually all laptops will have a 2.5" hard drive...most as the old fashioned "mechanical" drives, but more and more as SSDs).

5.25" is about the size of a typical hard cover book. 3.5" is about the size of a typical paperback book. And 2.5" is about the size of a deck of cards. Roughly speaking.

[LiveBrianD]

And a few laptops (very small ones) and older ipods have 1.8" hard drives. Slow 1.8" hard drives.

[Rommel]

tregg, on 10 August 2011 - 12:14 PM, said:

The 2.5", 3.5" and 5.25" Are these the measurements of the acutal disk? Is there a way to get this from the outside case dimensions?

I have a Seagate ST380817AS HDD.
It says it's a 3.5 form factor.

I measure it at 4" wide
5 3/4 long
1" thick.

Hope that helped.
??

[Tunz]

I just measured the actual size of a hard disk that I recently pulled from a failed drive and it measures 3.69", so it too is a "nominal" size.
They make great mirrors for a tool bag, as they are virtually indestructible.

[Szczecinianin]

Hi,
It's not too difficult, you just approximate. I took the dimensions of my HD and its CASE is 4,5" wide so I guess 3,5" is closest. And as to so called form factors you have some info here. With flash technology they can be really small.

[LiveBrianD]

Tunz, on 10 August 2011 - 08:23 PM, said:

I just measured the actual size of a hard disk that I recently pulled from a failed drive and it measures 3.69", so it too is a "nominal" size.
They make great mirrors for a tool bag, as they are virtually indestructible.

Not quite. I put a platter up against a pile of bricks and hit with a mallet. Eventually I made it bend quite a bit. It was difficult though.

[Tunz]

LiveBrianD, on 11 August 2011 - 02:12 PM, said:

Tunz, on 10 August 2011 - 08:23 PM, said:

I just measured the actual size of a hard disk that I recently pulled from a failed drive and it measures 3.69", so it too is a "nominal" size.
They make great mirrors for a tool bag, as they are virtually indestructible.

Not quite. I put a platter up against a pile of bricks and hit with a mallet. Eventually I made it bend quite a bit. It was difficult though.

LOL, I guess I'm a little gentler with them, but I like your style.

[LiveBrianD]

Tunz, on 11 August 2011 - 07:12 PM, said:

LiveBrianD, on 11 August 2011 - 02:12 PM, said:

Tunz, on 10 August 2011 - 08:23 PM, said:

I just measured the actual size of a hard disk that I recently pulled from a failed drive and it measures 3.69", so it too is a "nominal" size.
They make great mirrors for a tool bag, as they are virtually indestructible.

Not quite. I put a platter up against a pile of bricks and hit with a mallet. Eventually I made it bend quite a bit. It was difficult though.

LOL, I guess I'm a little gentler with them, but I like your style.

My way of making sure a hard drive that I'm about to get rid of is unreadable:
1. Run DBAN with the default 3 pass mode.
2. Open up the drive and whack the platters with a hammer. Hit it until it bends significantly, then turn it to a different direction and repeat, do that a few times.

I'm not comfortable with drilling holes in it. That could be an option for some though.