The extent to which an object has a common center or axis.


The angle beneath and behind the cutting edge, enabling the cutting edge to penetrate the workpiece to perform the metal cutting operation.

Axial runout

The relative difference in distance that two or more inserts/flutes protrude in the axial direction. Excessive runout will cause tool chipping or breakage.


A vibration condition between the tool and workpiece resulting in an inferior surface finish and potentially premature tool failure.


An obstruction placed in the path of the chip that curls and deflects the chip and causes it to break. On carbide inserts, chipbreakers can be ground or pressed.

Depth of cut (DOC)

The amount of penetration that a cutting tool makes into the workpiece. It is the distance from the uncut surface to the machined surface.

Edge preparation

The strengthening of the edge of a cutting tool with either a hone or chamfer.

Feed rate

The rate of tool travel through the workpiece per unit of time, generally expressed in inches per minute or inches per revolution.


Surface feet per minute, a measure of the velocity (speed) of the workpiece as it passes the tool.


Revolutions per minute, a measure of the spindle speed.