Here is my latest method to make square nuts on my Levin lathe. I am using 3mm square keys 50mm long for the stock. The first step is to square up the end. Sticking out of the collet just enough to remove the rounded end. I use the front tool first because it is much smoother on the corners than the back acting cutoff blade. There is a stop rod set for the front tool so it will only go deep enough to make the stock round.
Then the back acting cutoff blade cleans up the cut. The front blade is just a tiny bit thicker on the end face so it left a small landing on the bottom of the nut.
Now a spot drill followed by the tap drill. I can drill far enough for 9 or 10 nuts.
I have a lever collet closer so operating the collet is much quicker than a standard drawbar. I made a stock stop rod with a 8-80 thread which is a really fine thread and I wanted to use the tap and die I scored on ebay. What is not shown is the pusher rod to advance the stock.
The front tool adds the chamfer on the top of the nut and the washer detail on the bottom of the next nut.
I have a lever tailstock so I simply put the 1-72 tap in the drill chuck in the tailstock. This would not work with a screw type tailstock, but a sensitive drill attachment could be used. I spotted a lever one on ebay with a MT2 or a MT3 taper.
I use one hand to start feeding the tap and the other hand turns the spindle. There is a single hole in the top of my drawbar at my thumb so I count 5 turns in. The form tap starts to act as a lead screw after the first turn so the tailstock feed lever moves all by itself in and out.
The final op is to cutoff the finished nut. The cutting bit was ground at a slight angle so the nut drops off first with very little bur.
The finished nuts are shown.
I made 10 nuts in 15 minutes so I am really happy with the process and speed.
Cheers Dan