Overarm: The overarm bears the burden of the spindle and arbor assembly. It really is current along with the column. It can be often known as overhanging arm. Arbor: Arbor is really a sort of tool adapter (or tool holder) that supports adding a facet cutter or niche milling tools. https://millingmachinesaustralia24694.blogocial.com/not-known-facts-about-cnc-milling-machines-62909888