I have just made a vertical parting tool for my Stepperhead lathe. I first tried a normal parting tool mounted vertically but it suffered from scuffing on the parallel sides of the tool which is at the last part of contact with the metal being cut. So I made a one piece tool by silver soldering a small part of a high speed steel parting tool to a slightly thinner sheet of steel. Then I ground the high speed part to have clearance in both directions and it worked very well. It is nice and rigid in the cutting directions, with no bending for the parting tool. The mandrel rotates in a clockwise direction for a rear tool post which will be a problem for lathes with screwed on chucks so they would have to have the tool mounted at the front of the lathe. Here is a short video of it operating. It is only cutting off a 20mm dia. because I could not hold the camera and apply cutting oil with a brush at the same time but I will try it with larger diameters. But so far so good. Why has this not been tried before?
http://www.youtube.com/watch?v=S8HvS...lSWeYLoFlU2iA=

Alan