Fan Screws
Fan screws are coarse threaded and self tapping, because the mounting holes in a fan frame are plastic and unthreaded. That coarse pitch is what bites into the plastic and holds. A machine screw will strip that hole on the first install.
Stocked here: Phobya coarse fan screws in 4 piece packs, black and silver.
If you are mounting a fan to a radiator rather than to a case panel, you want a machine thread instead, normally 6-32 UNC or M3, and length depends on whether a shroud or filter is in the stack. Those are in 6-32 screws and the rest of the screws section.
