Framebuilders - Drilling holes in a frame

Hi, lately I've been looking into converting my single speed dirt jumper into an 8 speed dirt jumper, and when i was looking at the frame I noticed there was no 5mm hole for the derailleur to be installed. So I was wondering if drilling a 5mm hole into the frame(so I can install the derailleur) would be a good idea. And if not, what would be the best way to attach the derailleur.

Thanks for your time,

Rear derailleurs are not held on with 5mm bolts. Rear derailleur hangers are threaded M10x1- but you still need a hanger.

Depending on your drop outs you may be able to use something like one of these:
http://ecx.images-amazon.com/images/I/31Poxz8P%2BLL._SL500_AA300_.jpg

http://sheldonbrown.com/harris/tools/images/tl1460.jpg

Knowing what frame you have would make it easier- but in either case this is most likely not a permanent frame building fix so much as a mechanical addition.

The frame is from a KHS SJ-100. If that helps...

The frame is from a KHS SJ-100. If that helps...

What year? Looking at the website, the 2008 clearly shows a derailleur hanger. The 2011 may not. The frame color is throwing me off.

I believe it's a 2008. It is a white frame(if that helps). But there's nowhere to hang a derailleur. I think I might go with what Eric Estlund suggested. What are those pieces called(the ones in the pictures above)?

derailler hangers :) or derailler claws.

http://store.khsbicycles.com/derail-hanger.html

http://www.khsbicycles.com/StoreFiles/derhanger.pdf