Material removal in lapping operations In precision finishing (lapping), what is the typical total metal removed from a surface during the process?

Introduction / Context:
Lapping is an ultra-precision finishing method used to achieve very fine surface finishes and tight flatness tolerances using loose abrasives in a fluid vehicle between a lap and the workpiece.

Given Data / Assumptions:

• Final finishing after grinding or honing.
• Loose abrasive grains (e.g., Al2O3, SiC) on a soft lap plate.

Concept / Approach:
Lapping removes extremely small amounts of material, correcting minor shape errors and surface peaks left by previous processes. Excessive stock removal would defeat its purpose and consume undue time, as removal rates are very low compared to grinding or milling.

Step-by-Step Solution:
Estimate objective: improve flatness/finish, not major dimension change.Typical stock removal per surface is a few micrometres to a few tens of micrometres.Thus the representative range is about 0.005–0.01 mm (5–10 micrometres).

Verification / Alternative check:
Process data from lap equipment vendors indicate removal rates on the order of micrometres per minute for many metals.

Why Other Options Are Wrong:

• 0.01–0.1 mm and above are typical for honing/light grinding, not fine lapping.
• 0.5–1.0 mm or more is rough machining territory.

Common Pitfalls:
Expecting lapping to correct large geometry errors; using overly aggressive abrasives that scratch instead of polish.

Final Answer:
0.005 to 0.01 mm