ClipArt ETC
"The workpiece is fastened on a round platen, which in turn is attached to the table of a large and heavy vertical boring machine. The mill arbor bears a profile mill with inserted teeth, and the table has power feed. The operation is cheaper than turning in the lathe." —Grimshaw, 1902

Ring Milling

"The workpiece is fastened on a round platen, which in turn is attached to the table of a large and…