Page:Practical Treatise on Milling and Milling Machines.djvu/210

204 Milling Semi-Circle in Top of Spiral Head Base

The casting is clamped directly to the table, as clearly shown in the illustration, and the knee is raised so that the top of the piece is in a line with the axis of the cutter.

A shell end mill is used and the table is fed transversely, bringing all the cutting upon the end teeth of the mill.

When a mill is used in this manner, it is well to grind the teeth on the periphery a little smaller at the back end, as this has a tendency to prevent chattering.