I knurl a lot of aluminum, mostly 1/2". The tool should be 90 degrees to the work. Speed isn't critical but slow is fine. You can hand or auto feed very slowly. The piece of info that hasn't surfaced here, though, in case you weren't aware (I wasn't until I thought about it) - Knurling is like two gears meshing (the knurl wheel or wheels and the work) - and that meshing can only happen when the work is at one of the precise diameters that matches the knurling wheels' pitch. You can't just knurl any diameter! There are tables and the math isn't that hard to do. If you don't know the pitch of your knurling wheels just roll the tool along a piece of paper for a few inches and count the lines, do the math. (I built a little excel sheet so I could figure the right diameters for different pitch wheels.) To test - touch the knurl tool to the work very lightly. Rotate the lathe by hand a little over one revolution. If the knurl lines on the work line up with themselves as they come around, the diameter is correct. If you get a new set of lines - it isn't.