Page 145 - CITS - Fitter - Trade Theory

FITTER - CITS

3 Process of Lapping:
• Preparation: The workpiece and the lapping plate are cleaned thoroughly to remove any contaminants.
The lapping plate, typically made of cast iron or other materials, is mounted on a flat surface.
• Application of Abrasive Slurry: An abrasive slurry or compound, consisting of abrasive particles suspended
in a liquid, is applied to the lapping plate.

• Workpiece Mounting: The workpiece, which may be a flat component or a part with a concave or convex
surface, is placed on the lapping plate.
• Lapping Action: The workpiece is moved back and forth, rotated, or oscillated against the lapping plate
with a controlled pressure. The abrasive particles in the slurry abrade the workpiece surface, removing
material and refining the surface finish.

• Inspection: Periodic checks are performed to monitor the progress and ensure the desired surface quality
and dimensions are achieved.
• Cleaning and Final Inspection: Once lapping is completed, the workpiece and lapping plate are cleaned
thoroughly to remove any remaining abrasive particles. The workpiece is then inspected for surface finish,
flatness, and dimensional accuracy.
4 Process of Honing:

• Setup: The workpiece, typically a cylindrical bore or hole, is securely mounted on a honing machine or
fixture. The honing tool, consisting of abrasive stones attached to a rotating spindle, is inserted into the
bore.
• Application of Honing Oil: Honing oil or coolant is applied to the workpiece and honing stones to lubricate
the process, cool the workpiece, and flush away debris.
• Honing Action: The spindle rotates and reciprocates within the bore, causing the abrasive stones to remove
material from the bore’s surface. The honing process corrects geometry errors, such as out-of-roundness
or taper, and produces a specific surface finish.

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CITS : CG & M - Fitter - Lesson 23