What I'm uploading is stl's but not ones you would usually choose to print! These are intended as negative modifiers to make it easy to place holes in your parts within a slicer.

I've created through holes for countersunk M3 ISO screws/bolts. I've included various lengths in case you want to terminate a hole within a part.

The clearance holes should work for most needs but you can always choose to scale in X/Y if needs be. I recommend a test print where you make a simple cube then ‘load’ the negative modifier.

In order to use the stl's. Save to a folder and then use the right click, add negative volume>load…

Position the resulting clearance hole as you see fit.

I plan to add a whole series of these so look out for others. I will link as time goes by.