Haha, i just re-read your post and edited to suit.
The shanks are tough but not hardened steel so aslong as you dont mind milling a 1/16th off the bottoms you will be fine. After building up a set from shows and exhibitions of 11+ holders i can say that they are all full of tools ready to use – saves ages in setting tools up.
Edited By Rob Manley on 11/10/2009 14:28:14