Should a ball nose be used for only finishing passes? Or can they be used on 6061 T6 with roughing operations. I need to take out about 1" of material

Also how about Chamfer endmills? I have a 1/2" Chamfer mill with two blades. No blades on the shaft. I would assume this could only be used for a finishing pass correct?

Thanks R

example: mill a pocket 3x3x2deep..250 rad typ, T1.500 mill pocket,but leave a shoulder at the bottom for the .500 dia ball. T2: .500 ball mill, rough and finish bottom with ball mill. You can also leave matl. on the wall for clean up w/ ball mill.
as for the chamfer mill - let er rip...... with the right speed and feed.

There's no reason you can't use your ballnose for roughing out. It might not be the best way to do it, but it will remove material regardless.

Chamfer endmills are meant to turn a 90 deg edge into a 45 or whatever angle you got. Usually one pass no roughing/finishing.

There's no set rules on what a tool can "only" be used for, it's up to the operator and the practicallity of the application.