We've ordered half a dozen different screw assortments while searching for good replacement hardware for the Kobra X. One issue we've consistently run into is that many of the screws seem to have very little thread engagement from the factory, making it easy for the threads in the base to strip. In many cases, using a screw that's just slightly longer solves the problem.

If you plan to perform Y-axis maintenance on the printer, you'll need to remove the bottom cover. There's a good chance you'll encounter a few screws that won't tighten properly when you reassemble the printer, so having a selection of slightly longer replacements on hand can save a lot of frustration.

We've found an assortment of M3 screws on Amazon with the correct head diameter and Allen drive that works for about 95% of the screws used on both the Kobra X and the Kobra 4:

https://amzn.to/4wGNHeJ

The printhead uses even smaller screws, and the head dimensions need to match the originals. This assortment has worked well for those:

https://amzn.to/3SYU0Ma