Manufacturing Engineering 31 Questions & Answers.

01. Thermal cracking of tools occurs at

High temperature

Explanation: At high temperature tool may lose its hardness property which results in failure of tool and this phenomenon is known as thermal cracking.

02. Crater wear occurs at

Tool face

Explanation: Tool face is weaker for crater wear than shank or flank.

03. following is correct about crater wear.

Occurs more in soft tool

Explanation: Crater wear occurs in soft tools because their face gets eroded easily during flow of chips over the face.

04. Flank wear occurs at

Tool flank below cutting edge

Explanation: Tool flank are generally subjected to flank wear due to rubbing action of tool. Cutting edge may be side cutting edge or end cutting edge.

05. following will have a maximum amount of chips during machining.

Ductile material

Explanation: Ductile material produces more chip than brittle material.

06. In the orthogonal cutting of metals _________

the cutting edge of the tool is perpendicular to the direction of tool travel

Explanation: The cutting edge clears the width of the workpiece on either ends.

07. The factor responsible for the formation of discontinuous chips is


low cutting speed and small rake angle

Explanation: while high cutting speed and large rake angle of the tool will result in the formation of continuous chips.

08. Cutting forces can be measured using a

a) transducer
b) dynamometer
c) load cell
d) all of the mentioned.

Explanation: Cutting forces can be measured using a force transducer (typically with quartz piezoelectric sensors), a dynamometer, or a load cell (with resistance-wire strain gages placed on octagonal rings) mounted on the cutting-tool holder.

09. Crater wear occurs mainly on the

face of the cutting tool at a short distance from the cutting edge only

Explanation: Crater wear occurs on the rake face of the tool, while flank wear occurs on the relief (flank) face of the tool.

10. Crater wear is predominant in

tungsten carbide tools

Explanation: Crater wear is usually found while machining brittle materials and tungsten carbide tools favour this phenomenon.

11. Crater wear is mainly due to the phenomenon is known as

diffusion of metals

Explanation: Flank wear is due to the abrasive action and crater wear is due to diffusion of metals.

12. Crater wear leads to

a) increase in cutting temperature
b) weakening of tool
c) friction and cutting forces
d) all of the mentioned

13. Crater wear is usually found while machining 

brittle materials.

14. Flank wear occurs mainly on the

nose part, front relief face and side relief face of the cutting tool.

Explanation: Crater wear occurs on the rake face of the tool, while flank wear occurs on the relief (flank) face of the tool.

15. Tool life is generally better when

grain size of the metal is large.

16. The relation between the tool life(T) in minutes and cutting speed (V) in m/min is

VT^n = C

17. For machining a mild steel workpiece using carbide tool, the maximum material will be removed at a temperature of

100°c

18. For machining a mild steel workpiece by a high speed steel tool, the average cutting speed is

30 m/min

Explanation: For machining a cast iron workpiece by a high speed steel tool, the average cutting speed is 22 m/min and for a mild steel is 30 m/min.


23. Ceramic tools are fixed to a tool body by ___________

brazing

Explanation: These tools have greater tool life than carbide tools.

24. High speed steel tools retain their hardness upto a temperature of

900°c

25. In machining cast iron 

no cutting fluid is required.

26. The cutting fluid mostly used for machining alloy steels is :

sulphurised mineral oil.

27. The cutting fluid mostly used for machining steel is:

soluble oil.

Explanation: Soluble oils are used for machining metals of high machinability.

28. For turning internal tapers, the suitable method is

by a taper turning attachment.

29. Which of the following is also known as Puppet head?

Tailstock.

Explanation: Tailstock is also known as puppet head. It is at the back part of lathe machine.

30. following will give the best result for taper turning on the internal surface.

Using compound rest method.

31.  thread chasers is

Multipoint cutting tool.

Explanation: Thread chasers are multipoint cutting tool used for cutting threads.