Unicorn hat screws diameter

Hi all!

I would like to use the mounting holes of my unicorn hat for attach it to a project case. I am quite new at electronics and DIY so I am not familiarized with PCB screw standards and best practices.

What is the diameter my screws should have? I plan to use a nut in the backwards of the hat. Sounds that raesonable? Should I take any aditional caution?

Thanks in advance!

I think they’re the same as the Raspberry Pi mounting holes. M2.5 screws should fit as the holes are 2.75 +/- 0.05 mm.