250+ TOP MCQs on Tube Making and Answers

Casting, Forming and Welding Multiple Choice Questions on “Tube Making”.

1. Tube drawing process is very similar to bar drawing, except the input material is a tube.
a) True
b) False

Answer: a
Clarification: Tube drawing a kind of metal forming process which is very similar to bar drawing process, except the beginning of input material is a tube. This process is used to reduce the diameter, improve the surface finish and improve the dimensional accuracy of the metal tube. In this process, a mandrel may or may not be used, which mainly depends on the purpose.

2. The input of extrusion process is basically the output of tube drawing process.
a) True
b) False

Answer: b
Clarification: In general, the output of extrusion process can be the input of tube drawing process. In tube drawing process, the diameter and thickness of the tubes that have been formed by extrusion or other processes can be further decreased by tube drawing process. This process is almost similar to wire or rod drawing process except that it requires a mandrel to initiate the forming operation.

3. In tube drawing equipment, draw bench type uses multiple dies for completing the forming operation.
a) True
b) False

Answer: b
Clarification: In tube drawing process, the drawing equipment can be of several designs. In general, these designs are mainly classified into two types, which are draw bench and bull block. Draw bench type uses a single die and the pulling force is applied by a chain mechanism or by hydraulic system. It is mainly used for single length drawing of tube or rod.

4. Bull block drawing equipment is mainly used for drawing tubes of very long length.
a) True
b) False

Answer: a
Clarification: In general, the drawing equipment can be of draw bench or bull block type, depending on the purpose or required features in the tube. Bull block drawing equipment design is very similar to a rotating drum, and this equipment is mainly used for drawing the tubes or rods of very long length, which cannot be performed easily by having draw bench design of drawing equipment.

5. In tube drawing process, high dimensional accuracy of tube with close tolerances can be maintained.
a) True
b) False

Answer: a
Clarification: Tube drawing process is very economical and best suitable for producing tubes with thinner walls of high dimensional accuracy and close tolerances. This process is basically a cold working process which takes place at the room temperature or slightly above it. This process also provides better surface finish and enhances certain mechanical properties in the tube material.

6. Mandrel is a part of tube drawing mechanism, which is used for extracting out the tube from drawing mechanism.
a) True
b) False

Answer: b
Clarification: In the tube drawing process, when a hollow tube is drawn through a die, usually a mandrel or plug is used, which basically supports the internal diameter of the tube. The function of the mandrel mainly is to affect the wall thickness reduction and also used for controlling the shape and size of the hole in the tube.

7. The process of drawing a tube without the use of any mandrel is called as tube sinking.
a) True
b) False

Answer: a
Clarification: Tube drawing process can be performed with or without mandrel, depending on the features required in the drawn tube. The mandrel is generally excluded if it is not necessary to make a reduction in the wall thickness, or if the dimensions and surface finish are not important. The process of drawing a tube without the use of any mandrel is basically known as tube sinking.

8. The frictional problems can be increased if a long mandrel is used during the process of tube drawing.
a) True
b) False

Answer: b
Clarification: The tube drawing process can be accomplished by with or without mandrel. Mandrel basically consists of a hard rod or wire that extends over the entire length of the tube and is drawn through the die along with the drawing tube. The frictional problems can be greatly reduced by providing a long mandrel in the tube drawing process.

9. Removing of mandrel after the drawing process may disturb the dimensional tolerances.
a) True
b) False

Answer: a
Clarification: After tube drawing process, the mandrel should be removed from the tube which can be done by the reeling process. The removing process increases the tube diameter and also disturbs the dimensional tolerances. So, great care should be taken while extracting out the mandrel from the inside of tube.

10. In the tube drawing process, no any residual stresses are induced in the tube material.
a) True
b) False

Answer: b
Clarification: In the tube drawing process, the deformation is usually uniform throughout the tube. The process is a cold working process which causes residual stresses in the tube material. In general, the longitudinal residual stresses are tensile on the exterior surface and compressive on the interior surface of the tube.