I saw listing which was described as a "sunked screw head"-- which I know as meant for a countersunk hole that tapers.

Here is a copy of the photo where I can see a gap at the underside of the pan head. Is this a typo in the description or is this an actual head type?

The listing is on Aliexpress with no proper specification. I don't think I'll have much luck trying to ask the seller which is why I'm asking here.

enter image description here

  • Not sure what you're asking... it clearly is a thing, or are you doubting the photograph is real? – TylerH Oct 22 '20 at 14:40
  • 1
    I wonder if by "sunken" they mean an internal drive vs external (like a regular hex head screw, for example? – PhilippNagel Oct 22 '20 at 14:53
  • 6
    For what it's worth, I am not seeing any gap in the photo. It looks to me like there is a just a small taper at the shaft, and than the underside of the head is just flat. – PhilippNagel Oct 22 '20 at 14:56
  • 1
    This is a language problem. That screw looks like a pan-head sheet metal screw, i.e. not specifically designed to be counter-sunk. – Jimmy Fix-it Oct 22 '20 at 20:40
  • 1
    I agree with @AlaskaMan. Tell us the home improvement problem you are trying to solve by editing your question or the question could be closed as "off topic". – Jimmy Fix-it Oct 22 '20 at 20:42

I believe the gap you refer to is not actually a gap, but a bevel. That image seems to have a bit of an optical illusion that let me to see a gap at your arrow at first, but on further examination it looks like a standard countersunk screw.

  • 1
    It does not remotely look countersunk. – Pete Kirkham Oct 22 '20 at 23:09
  • 1
    I had to strain my eyes to see it but I think it actually tapering from the underside of the panhead towards the threads. It is an optical illusion that makes it look like it's beveling in the opposite direction and into the head itself. This also explains why different people are seeing different things. The whole part about it being a sunken head appears to be an error in the listing. – Zhro Oct 23 '20 at 10:17

PhilippNagel's comment is correct.

The bottom of the screw head is flat except where it tapers to the threaded shaft.

This taper seems to be no wider then the outer dimension of the threads so a countersink would not be necessary. (unless of coarse you wanted the top of the head of the screw to be flush with whatever it is installed in but that would not really be the correct fastener for that application.)


This aliexpress page has the same photo, and a diagram indicating that this M3.5 disk drive mounting screw has a flat mounting face.

Diagram of M3.5 HDD mounting screw

It's normal for a thread on a machine screw not to go all the way to the head, hence the transition to the full diameter.

The heads of HDD screws are somewhat flatter at four sides, maybe that flattening is what got mistranslated to 'sunked'.


Yes, it’s a typo, which is not surprising considering the source. There is no such word as “sunked,” therefore, no such thing as a “sunked screw head.”

Not the answer you're looking for? Browse other questions tagged or ask your own question.