Engineering Questions with Answers - Multiple Choice Questions
MCQs on Tool Maker’s Flats and High Precision Surface Plates
1 - Question
What is the shape of the tool maker’s flats?
a) Circular
b) Rectangular
c) Square
d) Triangular
View Answer
Answer: a
Explanation: Tool maker’s flats are small circular surface plates which are used for the high precision measurement work.
2 - Question
Which of the following is not true about tool maker’s flats?
a) Tool maker’s flats should be free from inclusions
b) Tool maker’s flats are of less hardness
c) Working surfaces are produced by lapping
d) Should be located in a stirred atmosphere
View Answer
Answer: b
Explanation: Tool maker’s flats should be free from inclusions which after proper heat treatment gives a high hardness. Working surfaces are finished by lapping to possess a high degree of accuracy and uniformity.
3 - Question
Why are shallow grooves provided in larger flats?
a) To minimize the possibilities of uneven hardening
b) For design purpose
c) To maintain high accuracy for a longer period
d) To make them lighter
View Answer
Answer: a
Explanation: A shallow groove is provided around the periphery of larger flats to avoid uneven hardening and for easy handling.
4 - Question
Which of the following is not true about the requirements of material selection for tool maker’s flats?
a) Suitable surface for the wringing purpose
b) High degree of rigidity
c) Wear resistance
d) Absorb radiant heat
View Answer
Answer: d
Explanation: Material should have a proper surface so that gauges can be wrung on to it and it should have a high degree of rigidity and freedom from warping. Material should reflect radiant heat.
5 - Question
What is the tool maker’s flat size which generally uses both the faces as a working surface?
a) 30 to 45 mm
b) 50 to 75 mm
c) 75 to 100 mm
d) 100 to 200 mm
View Answer
Answer: b
Explanation: Both the faces are highly finished in the range of 50-75 mm size and both are used as working surface and above this range it has only one face finished as working surface.
6 - Question
Which of the following hardness is given by Solid steel tool maker’s flats?
a) 93HRC
b) 83HRC
c) 73HRC
d) 63HRC
View Answer
Answer: a
Explanation: Solid steel tool maker’s flats after proper heat treatment gives a hardness of 93HRC or 850HV as high hardness is a desirable property for precision flats.
7 - Question
What is the minimum thickness of top in a high precision surface plate?
a) 20 mm for 350 mm dia
b) 25 mm for 250 mm dia
c) 30 mm for 250 mm dia
d) 20 mm for 250 mm dia
View Answer
Answer: d
Explanation: Minimum thickness of top in a high precision surface plate is 20 mm for 250 mm dia, 25 mm for 300 mm dia and 30 mm for 350 mm dia.
8 - Question
What is the advantage of granite over cast iron in making surface plates?
a) Reflects radiant heat
b) Won’t rust by moisture
c) Strength for given weight is high
d) No need of inserts and fasteners
View Answer
Answer: b
Explanation: Granite absorbs radiant heat which is a disadvantage. Granite won’t rust by moisture but may distort. Strength of cast iron is more than granite for a given weight.
9 - Question
Which of the following is true regarding high precision surface plates?
a) The top of high precision plate projects about 32 mm beyond the framing
b) The top of high precision plate projects about 32 mm below the framing
c) The top of high precision plate projects about 12 mm beyond the framing
d) The top of high precision plate projects about 12 mm below the framing
View Answer
Answer: c
Explanation: The top of high precision plates is machined around the sides and generally projects approx 12 mm beyond the framing.
10 - Question
What is the minimum total depth in high precision surface plates for 300 mm dia (nominal size)?
a) 60
b) 70
c) 80
d) 90
View Answer
Answer: c
Explanation: Minimum total depth for 250, 300, 350 mm dia is 70, 80, 90 mm respectively.
Explanation: Minimum total depth for 250, 300, 350 mm dia is 70, 80, 90 mm respectively.