Question

Seamless tubes can be produced by

• A. rolling
• B. extrusion
• C. deep drawing
• D. forging

Hint:

Whenever a question asks about producing continuous hollow profiles, think of Extrusion with a mandrel.
For non-continuous cup-like hollow parts, the correct choice would be Deep Drawing.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks which metal forming process is used for manufacturing seamless tubes.
Seamless tubes do not contain any welded joints along their length, which makes them highly reliable for high-pressure applications.

Step 2: Key Formula or Approach:
Manufacturing of tubes can be categorized into welded and seamless tube production.
Processes like extrusion and rotary tube piercing (Mannesmann process) are specialized techniques for creating hollow, seamless cylindrical shapes.

Step 3: Detailed Explanation:

• Extrusion: In metal extrusion, a billet is compressed and forced to flow through a die. For producing hollow tubes, a mandrel is placed inside the die. As the metal is squeezed through the annular gap between the die and the mandrel, a continuous seamless tube of uniform cross-section is produced. This process can be performed hot or cold.

• Rolling: Standard rolling processes are used to produce flat sheets, plates, or structured shapes. While specialized tube-rolling processes exist, standard rolling is typically associated with flat products.

• Deep Drawing: This process is used to form sheet metal into cup-shaped or box-shaped containers, rather than continuous long pipes.

• Forging: Forging is a localized deformation process using compressive forces. It is not suitable for producing long, continuous, thin-walled hollow sections like seamless tubes.

Step 4: Final Answer:
Therefore, seamless tubes are primarily produced by extrusion.