Hi Jeff.
Concrete drills come in different sizes, I used a 4 flute ball end milling cutter.
On the left are 4 carbide inserted drills, 1 solid one. On the right is a ball end milling cutter.
Use slow rpm, with continued pressure, oil the drill well.
At the bottom you'll have heavy burr, stone or hone it.
So far the sausages were good no matter which grinder I used.
Ps.....I like my newest all stainless steel grinder, size 22, with the so called big bite screw, 1 and 1/2 hp. Of course after I made the plates and knife flat.
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My new all stainless grinder does rust. Looks very nice, mirror polished, magnet doesn't hold it......

Failure to prepare is preparing to fail.