Chip formation vs tool edge condition When the cutting edge becomes dull due to wear, what chip type is most likely to appear (under typical ductile-work cutting)? Choose the best answer.

Concept
A dull tool increases friction and temperature at the tool–chip interface, promoting built-up edge on ductile materials. BUE causes poor surface finish and fluctuating cutting forces.

Eliminations
(a) Clean continuous chips are more typical with sharp tools and good lubrication.(b) Discontinuous chips are more typical with brittle materials or very low cutting speeds, not solely due to dullness.(d) Chip formation continues unless cutting stops.

Final Answer
Continuous chips with a built-up edge (BUE) on the tool.