A while back a thread started about forging files with or without teeth. I forged this knife from a file in which I ground most if not all the teeth from the edges and about 80% from the sides. The knife was then ground, heat treated in such a way as to get a hammon (I was experimenting on methods). After it was ground I didn't see any defects so it was etched, and low and behold, inclusions at the edge.

I tried forging a knife years ago without removing th eteeth. When I quenched it, it had spider cracks all over it. Figured the teeth were just so many stress risers.