I have in the past run into this issue where I bought a used HP item from eBay and it was missing the M.2 mounting screw that HP uses. It's not the usual M2 or M3 screw thread... more like M1.6 with a black plastic piece that holds the M.2 SSD. I have a Z Turbo Drive G2 that is also missing this mounting screw. The same was also found in some HP T620 Plus thin client machines too. Not really sure what the part number is?
1. Never buy a HP ZTD generation 1 or 2 PCIe card from eBay without informing the seller ahead of time to not accept the purchase if that very specific hold down brass/black plastic/ tiny metric screw is NOT included. Those are not standard size M.2 hold down screws... they are very much HP specific. The seller will say oops if you buy and it was in the picture and yet not included, but you won't get your screw. You might get your money back, with significant hassle. Clarify it ahead of time.
2. Don't over-tighten them... gentle snug only. Those threads can "gall" and freeze up. Look up galling, or "to gall". Don't ask how I know.
3. You don't really need one if you have the Generation 2 version with the aluminum heatsink that will gently clamp down on the M.2 drive via the thermal foam pads above and below. You can use one of those heatsinks from a generation 2 ZTD on a generation 1 ZTD. Take a look... it does not take much to hold that M.2 stick in place.
4. You could do us a favor and go on to McMaster.com and look at their metric tiny machine screws, and buy one of each of the tiny ones and check it against a correct HP one, and let us know exactly what the metric diameter and thread pitch specifications are so everyone in the future could know at least what threads would fit.
5. Best solution is #1 above.
6. Worst solution is buying a second HP PCIe M.2 card just to get the special HP screw (which is what I did because I found a great deal on a second card).
@SDH : I appreciate the reply, but doesn't really help the current situation.
I did figure out that the thread size is indeed M1.6. Still, would rather find the HP part number for the above screw and wish I could buy replacements somewhere.
My final solution will be to drill out the threads with a 1.6mm drill bit and then tap in M2 threads. M2 wafer head screws are very easy to find in many lengths. I can use that with some nylon washers to use a spacers and come up with a make shift solution.
Be alert for scammers posting fake support phone numbers and/or email addresses on the community. If you think you have received a fake HP Support message, please report it to us by clicking on "Flag Post".