Tech Talk
What is a "Shell Mill"?
The shell mill is a milling cutter which fills the gap between solid one-piece end mills and the large-diameter face mills. Unlike the other standard one-piece tools described to this point, the shell mill is an assembley: the cutter is designed to be mounted on an arbour or adapter which serves as the driving shank. The method used to secure the shell mill on the arbour varies from tool manufacturer to tool manufacturer, but generally involves keying the components to provide positive driving action and prevent relative motion.
The cutter teeth extend around the end of the tool, making it suitable for facing as well as slabbing cuts. The teeth do not extend to the centre, so the tool cannot be used for plunge cuts. Shell mills are available as standards in cutting diameters ranging from 1-1/4 to 6 inches and in cutting width from 1 to 2-1/4 inches. They are commonly used for milling flats and shoulders perpendicular to the tool axis, in ferrous and nonferrous metals. The cutter teeth can be obtained with sharp, beveled or rounded corners depending on the users job requirements.
