Attached is a pic of a linkage ball that i need to make hundreds of. Very small, ball diameter is 5.25mm, through hole is 2mm, diameter at base is 4mm. My machine does not have a sub spindle so im trying to come up with a parting strategy that will leave the part finished without a burr. I havent ran any yet, so the first thing ill try is just parting it off with a very thin sharp carbide parting insert that is biased to one side, front edge of parting insert has 7 degree angle so the point of it breaks through the part side first. This may still leave a ring of material around the 2mm through hole. Another idea i had was to run the parting op before the 2mm through hole. Parting op will run to a depth just a few thou beyond the edge of where the 2mm bore will be. After that i will drill the 2mm hole that will meet up with the parting feature and separate the part. At this point the part will be sitting on the drill, which can feed over to a fork, drop down over it, and back up to push the part off of the drill into a container.

so im wondering if this could possibly leave a cleaner part off line vs just doing the parting op last. When the drill breaks the part free, there will most likely be a ring of material there at the back corner, but the drill will continue to feed through into the bar stock behind the part. I would think the little ring of material left on the part would get sandwiched between the drill and bar stock, effectively removing it and leaving a nice clean part off. Has anyone tried using a drill for parting off like this?