Great Tool your the 2nd machinist ive seen in ~ 40 years to use these 'bifurcated'. toolNow it's back to the lathe to turn the first throw journal. I use high speed tooling on my cranks. That's not to say that carbide can't be used, I just like high speed for this type of work. I can put a much sharper edge on it and hone it if it gets a little dull. The tool I use for the throws is like and extended cutoff tool made long enough to get to the bottom of my cut. It has clearance on both sides so I don't scuff the sides of the throws. The width is already finished on the mill. I only need to make it round and to size. When you start out the cut will be intermittent but not as bad as trying to cut all of the stock out on the lathe. The nose shape is what's refered to as 'bifurcated'. It has a notch gound into it so that you're only cutting with the 2 small outboard edges. The total width of the nose is a little less than 1/2 the width of the throw. This allows you to move the tool back and forth to clean up the whole journal. There is also a small radius on the corner. This gives the crank strength at the junction point. When first setting up the tool mount your dial indicator somewhere and indicate across the 2 points on the tool. This is very important to get a parallel cut on the journal.
