Yeah, I'm a drilling and tapping fool. I got a set of Dubro drills and taps and they cover all of the sizes that you need for RC. If you don't want to get the whole set, the 3mm screws common to RC are 3mm by .5mm pitch. I used the standoffs that held my mechanical brake pads in place and four 3mm washers. These fans move some air.

BTW, I'm also a soldering fool. Almost all of these fans that I've seen come with this little bitty 28 gauge wire. I have some leads that I made using 20 gauge silicon jacketed wire with jst plugs. I remove the stock wires from the fans and replace them with my leads. Just being anal, but I have had a few of the stock wires break.