I do one part that has a straight knurl about 25mm long. 6061 aluminum, about 30mm diameter. Not sure what size the tool is, maybe 20mm or so. I just set the depth and feed in from the front at about 0.2 mm / revolution, turning about 300 RPM. Flood coolant. Seems to come out fine each time. I'm doing this in a CNC lathe, but have used the same procedure on a manual lathe.