The dead metal zone appears in particularly when machining with high rake angle or when using chamfered and/or honed cutting tool edges independently of the used work material. It supposed to exist during the steady state condition. However, the BUE formation is governed by the characteristics of the work material. It appears during the machining ductile or soft materials under low cutting speed. It can be stable or note depending on the used cutting speed range. hence, the BUE is related to the physical/thermal work material properties while the DMZ formation depends on the geometry of the used cutting  tool.