Even it's commercial, it's nice technical documentation of cutting tool especially the chapter "material to cut".

The link below
http://www.hoffmann-group.com/download/en/zerspanungshandbuch/en-zerspanungshandbuch.pdf

:)

Wow, that book has a lot of really nice information. I especially liked the pictures of various chips with the little emoticons next to them showing the favorability :) Thanks