When he cuts out the waste at around 2:30, it is fascinating to see how that blade turns to horizontal. [eek] [eek] I thought only a very narrow blade could do that. Slick.
It's a special type of blade which I think has not been made in decades. I read somewhere about somebody finding a few NOS and how excited Frank was to receive one of them. In addition to having the blade forged to twist like that I think the teeth are graduated.