Here is a 1/2″ high strength steel Hexagon Broach, push type, for use with arbor or hydraulic press. This converts a round hole into a hex, in just one pass. The length of cut based on mild steel. This broach is excellent to use for aluminum, mild steel, and it cuts plastic like butter. When broaching metal, also use a cutting fluid as the press is taking place.

If your robot designs are using more and more hex products, you may as well have a broach!