Mill-Turn / Multi-Tasking Machines

A mill-turn machine, also called a multi-tasking machine, is a lathe with a real milling spindle. Next to the turning spindle sits a milling head on a B axis, fed from a tool magazine, that can turn, mill, drill and tap at any angle. Most have a second spindle to take the part over and finish the back. The aim is one setup: bar or billet goes in and a finished part comes out, with no queue between a lathe and a mill and no error from re-clamping.

The difference from a CNC lathe with driven tools is the scale of the milling: a full spindle with its own tool taper against small tools in a turret. Many mill-turn machines add a lower turret so that two tools cut at once. Against a 5-axis machining center, the mill-turn is the choice when the part starts round and has long turned sections, and the machining center when the part is mainly milled.

Compare the turning envelope first, maximum diameter and length. Then the milling side: spindle speed, power, taper and the B-axis range. Y-axis travel decides how far off centre the machine can mill. Tool magazine capacity matters more here than on a lathe, since one setup needs every tool. Check the second spindle and the lower turret, which are often separate variants of the same model.