Depth of cut is the depth of material removed in a single pass.
Together with cutting speed and feed, it is one of the basic elements of cutting conditions.
A Closer Look
A larger depth of cut removes more material at once, finishing the job in fewer passes.
But it also increases the load (cutting force) on the tool and machine, and can cause the workpiece to deflect or chatter (vibrate).
The depth of cut should therefore be set within what the rigidity of the machine and workpiece can comfortably handle.
On long, slender workpieces in particular, a large depth of cut invites deflection, so the cut is often kept shallow and taken in several passes.
The basic approach is a larger depth of cut for roughing and a small depth of cut for finishing to bring precision and surface quality into line.