Tool wear mechanisms: On which regions of a single-point cutting tool does flank wear primarily occur during metal cutting?

Introduction / Context:
Tool wear governs surface finish, dimensional accuracy, cutting forces, and tool life. Two dominant wear types on single-point tools are crater wear (on the rake face) and flank wear (on the relief faces). Understanding where flank wear appears helps in setting change criteria and selecting cutting conditions.

Given Data / Assumptions:

• Continuous turning with a single-point tool.
• Typical steels/nonferrous alloys, no severe build-up edge assumed.
• Normal feeds and speeds.

Concept / Approach:
Flank wear is abrasion/adhesion wear on the relief faces that rub against the newly generated work surface. It is measured as land width on the side and end relief faces and is usually most pronounced at/near the tool nose where contact pressure and temperature are highest. Crater wear, by contrast, forms on the rake face due to chip flow and is a different indicator.

Step-by-Step Solution:

Verification / Alternative check:
Inspection under a toolmaker’s microscope shows a bright, flattened land on the side/end relief faces, greatest at the nose. ISO wear criterion often limits VB (average flank wear land) and VBN (nose wear).

Why Other Options Are Wrong:

• Rake-face-only wear away from edge describes crater wear, not flank wear.
• Wear exactly along a sharp line is unrealistic; flank wear forms a finite land.
• Chisel point/rake-only statements misidentify the mechanism.
• Shank wear is irrelevant to cutting performance.

Common Pitfalls:
Confusing crater and flank wear; measuring only nose recession and ignoring side land; running tools until catastrophic chipping instead of using VB limits.

Final Answer:
Nose region, front (end) relief face, and side relief face