If the depths are all 0.180" then I see if 0.187" is ok, then do them as
through holes in a sheet of 3/16" plate, then bolt that to a backing plate.
Saves all the agony of a good surface finish on the bottom of each pocket.
Otherwise without cnc I think your approach is probably best.

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Regards,
Carl Ijames
"Tom Gardner" wrote in message
...

I have to mill 32 round pockets into an AL plate. The pockets range from
2.125" dia. x .180" deep to 2.625" dia. x 1.80 deep. This plate will be a
mold for injecting Urethane into thin wire wheel brushes that are used to
clean grooves and such. This encapsulating process is done by another
company that is a trading partner and good friends. They just don't have
much machining capability. In return, I get a hot stamping machine that I
have good use for.

Very much like this:
http://atdtools.com/8245

My first thought is to use a large end mill and do the center of the pocket
then enlarge the dia. with a boring head. Any other ideas?