Question

In which of the following surface finishing operation; the relative motion between tool and the previously machined surface is a combination of reciprocation and rotary motions?

• A. Lapping
• B. Buffing
• C. Tumbling
• D. Honing

Hint:

Think of Honing as Helical. Because the tool turns while moving up and down, every abrasive grain follows a helical path, ensuring that no single grain follows the same path twice.

Answer 1

The Correct Option is D

1. The Honing Process:

Honing is an abrasive machining process used primarily for finishing internal cylindrical surfaces, such as engine cylinders. The tool, called a hone, consists of several abrasive sticks (stones) mounted on an expandable mandrel.

2. Complex Motion Pattern: The defining characteristic of honing is its simultaneous dual motion:

• Rotary Motion: The honing tool rotates slowly within the bore.

• Reciprocating Motion: The tool also moves back and forth (oscillates) along the axis of the bore.
This combination creates a distinctive

cross-hatch pattern on the surface. This pattern is functionally critical in engine cylinders because it helps retain lubricating oil during engine operation.

3. Analyzing Other Operations:

• Lapping: Uses a flat plate with loose abrasive. The motion is typically a complex, multi-directional "figure-eight" path, but it is not a standardized axial reciprocation combined with rotation.

• Buffing: Uses a rapidly rotating soft cloth wheel with fine abrasives. It is purely a rotary finishing process.

• Tumbling: A mass-finishing process where parts are rotated in a barrel with abrasive media. The motion is random and dictated by the gravity and rotation of the drum.