Quote Originally Posted by jinsean View Post
Hmmm, stupid question: do I have to tread the hole? I don't know how thick the metal is on the rad, but it seems that for like 1-2mm thickness I could probably get by without treading... please correct me if I'm wrong. I'm not an expert on tools.
You can use self tapping screws...
Or buy a tap, a tap wrench (little thing that holds the tap and has a handle), insert the tap into the hole, and start twisting. The metal is very thin, just go a little bit in and you're good.