Recent content by 40Tudor

I knew I had seen something like this before (April 1956 Pop Sci). Wonder how the head in the video works. http://books.google.com/books?id=NC0DAAAAMBAJ&lpg=RA1-PA214&ots=3OjCWFbJqo&dq=popular%20science%20square%20drill%20bit&pg=RA1-PA214#v=onepage&q&f=false