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Screw threads

  • Thread starter Dirk Bruere at NeoPax
  • Start date
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk
 
P

PeterD

Jan 1, 1970
0
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk

6-32 in most cases. All other fasteners on drives are usually metric.
 
D

Donald

Jan 1, 1970
0
Dirk said:
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk
Did you try one ??

Did it fit ??

The screws for mounting a hard drive have not changed since 1985.

I do know that one set of holes in the side of the drive is metric and
the other set is standard(US).

Is there a reason you need a real number ??

donald
 
M

MooseFET

Jan 1, 1970
0
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk

I've got several disks here. Perhaps they aren't the same model but
I'll tell you what these use. All screw holes for mounting are
standard #6-32. This makes sense because the casting is aluminum.
You wouldn't want a finer thread than that into aluminum.
 
D

Dirk Bruere at NeoPax

Jan 1, 1970
0
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk

Thanks for the replies - US 6/32
The reason I need the thread is that I'm fitting HDDs into a custom
carrier made from thick Al for heatsinking.
The screws supplied with each HDD are not long enough, so I have to
source ones a bit longer, ideally with countersink heads.

Dirk
 
R

Roger Hamlett

Jan 1, 1970
0
Dirk Bruere at NeoPax said:
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk
It depends.
There are two standards. 6-32UNC, and M3. Historically, drives made for
the US market, had the former, while those made for the European/Japanese
market had the later. You can even get the same drive, with both thread
types from some manufacturers. I had 'joy' a few years ago, when having to
source replacement drives in quantity, and the only ones available at the
time, had the metric threads, where the originals sourced via the US, had
the imperial threads...
Generally 6-32, is the more common fitting on the 3.5" drives.

Best Wishes
 
K

krw

Jan 1, 1970
0
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.

6-32 x 5/8", IIRC.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.

Those are 2.5mm, or some such; much smaller.
Anyone know for sure?

6-32 is definite, though 5/8" seems long.
 
E

Eeyore

Jan 1, 1970
0
Dirk said:
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Oh it's one of those funny US threads. 4-40 IIRC.

They are the same screws as mainly used elsewhere in the case btw, although
there may have a few instances where a metric therad was used by some
manufacturers.

3.5" floppies and CD/DVD drives use M3 screws btw.

Graham
 
E

Eeyore

Jan 1, 1970
0
PeterD said:
6-32 in most cases. All other fasteners on drives are usually metric.

6-32 is larger I think.

Graham
 
R

Rich Grise

Jan 1, 1970
0
Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

You use screws on your drives? I just lay them on that little platform. ;-)

Cheers!
Rich
 
R

Rich Grise

Jan 1, 1970
0
Thanks for the replies - US 6/32
The reason I need the thread is that I'm fitting HDDs into a custom
carrier made from thick Al for heatsinking.
The screws supplied with each HDD are not long enough, so I have to
source ones a bit longer, ideally with countersink heads.

Go find someone who has a thread gauge. :)

Good Luck!
Rich
 
R

Robert Baer

Jan 1, 1970
0
Dirk said:
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk
I have seen two types; US 6-32 and metric (slightly smaller, i think).
Some drives allowed both types and most other drives take 6-32 only.
 
R

Robert Baer

Jan 1, 1970
0
MooseFET said:
I've got several disks here. Perhaps they aren't the same model but
I'll tell you what these use. All screw holes for mounting are
standard #6-32. This makes sense because the casting is aluminum.
You wouldn't want a finer thread than that into aluminum.
One can have as fine a thread as one wishes (say 80TPI max); the
alloy makes no difference.
 
R

Roger Hamlett

Jan 1, 1970
0
Robert Baer said:
One can have as fine a thread as one wishes (say 80TPI max); the alloy
makes no difference.
In soft materials, you get greater ultimate strength using a coarse
thread. This is why the 'standard', is to use coarse threads in soft
alloys, and finer threads in harder materials. You can cut a fine thread,
but for structural strength you want it coarser. Historically, the old
'Whitworth' threads, were the result of quite a lot of research, trying
different tooth shapes and pitches, to maximise strength in soft
materials, and the UNC threads, are very close indeed to the same (in
general, just changed the tooth shape to a 60 degree form, that is
slightly easier to machine, than the 55 degree shape used on the Whit
threads). The 'standard' metric thread (unless a pitch is specified), is
actually the coarser of the metric normal forms, being reasonable for
harder alloys, but rather too fine for soft aluminium. Stupidly, this is
used as being 'easy' in a lot of places, despite it being less than
optimal.
If you look at the studs used on PC cases, those made by 'better'
manufacturers, have a coarse thread on the stud designed to screw into the
alloy case, and a finer thread on the inside to take the screw (cheaper
manufacturers don't bother, and use the same thread on both parts...).
Fortunately, in general, the actual strength needed in PC parts, is tiny,
compared to the ultimate strength, so people 'get away' with poor thread
selection.

Best Wishes
 
R

Ross Herbert

Jan 1, 1970
0
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
I've sent an email to Seagate, but no reply so far.
It seems a simple question but I just can't find the answer on the
net.
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.
Anyone know for sure?

Dirk


The information you are looking for is on the Seagate website.

Go here
http://www.seagate.com/www/en-us/support/installation_assistance/ and
select for example ATA Hard Drives and you will find the screw size
and thread.
 
M

Michael Brown

Jan 1, 1970
0
Roger said:
Dirk said:
Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.
[...]
It depends.
There are two standards. 6-32UNC, and M3. Historically, drives made
for the US market, had the former, while those made for the
European/Japanese market had the later. You can even get the same
drive, with both thread types from some manufacturers.

Here in Australia, things are dicier still. I've got two identical Seagate
7200.10 drives, bought a couple of months apart from different vendors. One
uses 6-32 screws, the other uses M3's. I've recently bought a few Samsung
501LJ's and they all use M3's. The older SCSI drives I've got use 6-32's.
Self-tappers and a strong screwdriver are starting to look enticing :)

[...]
 
J

Jasen Betts

Jan 1, 1970
0
Hi

Trying to find out what screw thread is used to fix hard disc drives
into a PC chassis.

6-32 UNC
I do know that the thread is not the same as regular PC chassis screws
even though the screw looks similar.

the other screw used is M3, it fits crdom drives etc...

Bye.
Jasen
 
J

Jasen Betts

Jan 1, 1970
0
One can have as fine a thread as one wishes (say 80TPI max); the
alloy makes no difference.

Coarse threads work better in soft alloys for a number of reasons
eg: less risk of stripping the threads or cross-threading.

Bye.
Jasen
 
E

Eeyore

Jan 1, 1970
0
Robert said:
One can have as fine a thread as one wishes (say 80TPI max); the
alloy makes no difference.

Rubbish. I suggest you try cutting one.

Graham
 
R

Robert Baer

Jan 1, 1970
0
Eeyore said:
Robert Baer wrote:




Rubbish. I suggest you try cutting one.

Graham
Have done it a few times; no problems.
Usually the finest i do is 2-56 tho.
 
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