In the up-milling process, the metal is removed in the form of small chips by a cutter rotating _____.

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RRB JE CBT 2 (Mechanical Engineering) ReExam Official Paper (Held On: 04 Jun, 2025)

Answer 1

Explanation:

Up-Milling Process

The up-milling process, also known as conventional milling, is one of the two main methods used in milling operations. In this process, the cutting tool rotates against the direction of the feed of the workpiece. This means that the cutter teeth engage the material at the beginning of the cut with a small chip thickness, which increases progressively to the maximum thickness as the tool leaves the material.
During the up-milling process, the cutting tool pushes the workpiece in the opposite direction of its feed. This results in a gradual buildup of chip thickness, which is advantageous for certain types of machining operations. The cutter tends to push the workpiece away from the tool, which can lead to vibrations if the setup is not rigid. The process generally requires more force to cut as compared to down-milling.

Key Characteristics of Up-Milling:

The cutting tool rotates against the direction of the feed of the workpiece.
Chip thickness starts small and increases as the cutter progresses.
It is suitable for machining materials with hard surfaces or for rough cutting operations.
The cutting force tends to lift the workpiece, requiring a firm clamping setup to avoid movement or vibrations.
Tool wear is relatively higher compared to down-milling due to the increased friction at the start of the cut.

Applications:

Used in machining operations where a rough surface finish is acceptable.
Preferred for machining workpieces with abrasive or hardened surfaces, as the gradual engagement of the tool reduces the initial impact.
Commonly used for milling operations on uneven or dirty workpiece surfaces.