wrote:
What is the thread size for screws to mount a HDD or Floppy drive?

I know they are very small, and vary in length, but I think they are all
the same thickness and thread pitch. I need to see if I can get these at
a local hardware store, or else I will have to go to ebay.

Anyone know the specs on them?


Reference section at top, comments (live action) at bottom.

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Page 29 (960,162 bytes)

https://www.seagate.com/staticfiles/...100529369b.pdf

Use only 6-32 UNC mounting screws.

The screws should be inserted no more than 0.150 inch (3.81 mm)
into the bottom or side mounting holes.

Do not overtighten the mounting screws (maximum torque: 6 inch-lb).

https://en.wikipedia.org/wiki/Computer_case_screws

"The #6-32 UNC screws are often found on hard disk drives
and the case's body to secure the covers.

The M3 threaded holes are often found on optical disc drives
and floppy drives.

Motherboards and other circuit boards often use a #6-32 UNC standoff.

#4-40 UNC thumb screws are often found on the ends of
DVI, VGA, and older Serial and Parallel cables."

https://en.wikipedia.org/wiki/Comput...6-32_UNC_screw

a major thread diameter of #6 which is defined as 0.1380 inches (3.51 mm)

and 32 tpi (threads per inch) which equates to
a thread pitch of 0.031250 inches (0.7938 mm)

It commonly appears in lengths of 3/16 inch, 1/4 inch, or less often 5/16.

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OK, so I dug out a few samples.

The PCI slot cover is 6-32, with the threaded section being 1/4" worth
of threads, and the hex sided head with Philips drive bringing it
up to about 3/8" long.

https://en.wikipedia.org/wiki/Comput...slot_screw.jpg

The disk drive screw on the other hand, was 6-32, but the total
length of the screw was 1/4", and the head is flat. That's the
pan head.

https://en.wikipedia.org/wiki/Comput...6-32-large.jpg

The optical drive screw has a finer pitch and is 1/4" long for the
whole thing. That's probably the M3 one. For the optical drive
screw, we can use this picture (bottom). Now, this picture isn't
entirely correct - the bottom screw has the right pitch, but
it needs the pan head on it to be the optical drive screw.
Drive screws have the flat head (like the picture above)
so there is no chance of the screw snagging on the rails
as it slides into stuff. The screw on the optical drive
doesn't fit the hard drive. But the screw holding a PCI
slot cover, fit into the hard drive, even if it is too long.

https://en.wikipedia.org/wiki/Comput...read_pitch.png

This references shows the shapes by name. The one on the left,
the "pan", is the head shape for both HDD and ODD. This is
from the Wikipedia article entitled "Screw".

https://en.wikipedia.org/wiki/Screw#...head_types.svg

(a) pan, (b) dome (button), (c) round, (d) truss (mushroom),
(e) flat (countersunk), (f) oval (raised head)

HTH,
Paul