Sometimes GPU fan screws go missing, and sometimes the only way to get a bargain on a used GPU is to buy one with a missing fan. There is a pretty good chance that you won’t have any suitable GPU fan screws in your parts stash. In my case, the smallest screws I had in my parts stash were M2 screws, commonly used on laptop hard drives and SSDs. But they were too big for the shroud on a GTX 1050 TI that needed a replacement fan.
I was able to salvage screws from a GT 210 that we weren’t using for anything. The screws to hold its fan happened to fit, even though the card and fan are much smaller. But if you don’t have a card to plunder, you have to find some screws.
What size screws for a GPU fan?
Some likely candidates are 0-80 or 1-72 machine screws, or 1.4mm machine screws. These tiny machine screws are not something you find in a typical hardware store. Outside of GPUs, their most common use is in eyeglasses or small scale model railroads.
So your best bet is to procure an eyeglass repair kit that has assorted screws, and try various sizes until you find the best fit.
When you go to replace the screws, test the fit before you put the GPU fan in place. After you test the fit, it’s not a bad idea to use thread locker on the replacement GPU screws to make them less likely to accidentally back out on you. GPU fans sometimes run at extremely high speeds, and they also frequently will vary their speeds, and the result of all of this can be a great deal of vibration. Thread sealer can help the GPU screws to stay where they are supposed to stay, so you don’t get more problems.