High tool hardness

High thermal conductivity of the work material

Poor tool roughness

Chemical affinity of tool material with iron

High tool hardness

High thermal conductivity of work material

Poor tool toughness

Chemical affinity of tool material with iron

$$HSS$$

tungsten carbide

$$CBN$$

diamond

increase in the effective rake angle and a decrease in the effective clearance angle

increase in both effective rake angle and effective clearance angle

decrease in effective rake angle and an increase in the effective clearance angle

decrease in both effective rank angle and effective clearance angle