Deck 20: Economic and Product Design Considerations

Question 1

Which of the following criteria are generally recognized to indicate good machinability (four best answers):

A)ease of chip disposal
B)good surface finish
C)high cutting temperatures
D)high power requirements
E)long tool life
F)low cutting forces
G)zero shear plane angle

Answer 1

ease of chip disposal
good surface finish
long tool life
low cutting forces

Question 2

Of the various methods for testing machinability, which one of the following is the most important:

A)cutting forces
B)cutting temperature
C)horsepower consumed in the operation
D)surface roughness
E)tool life
F)tool wear

Answer 2

tool life

Question 3

A machinability rating greater than 1.0 indicates that the work material is

A)easier to machine than the base metal
B)more difficult to machine than the base metal where the base metal has a rating = 1.0

Answer 3

easier to machine than the base metal

Question 4

In general, which one of the following materials has the highest machinability:

A)aluminum
B)cast iron
C)copper
D)low carbon steel
E)stainless steel
F)titanium alloys
G)unhardened tool steel

Question 5

Which one of the following operations is generally capable of the closest tolerances:

A)broaching
B)drilling
C)end milling
D)planing
E)sawing

Question 6

Which of the following are geometric factors in a machining operation that determine the surface geometry of the work part (three best answers):

A)cutting speed
B)depth of cut
C)ductility of the work material
D)feed
E)nose radius on the tool
F)type of machining operation

Question 7

The actual surface roughness R_a almost always has a lower value than the ideal surface roughness R_i:

Question 8

When cutting a ductile work material, an increase in cutting speed will generally

A)degrade surface finish which means a higher value of R_a
B)improve surface finish which means a lower value of R_a

Question 9

Which one of the following operations is generally capable of the best surface finishes, which means the lowest value of R_a:

A)broaching
B)drilling
C)end milling
D)planing
E)turning

Question 10

When selecting the appropriate cutting conditions for a given machining operation, which of the following parameters should be selected before the other:

A)cutting speed
B)feed

Question 11

Which of the following time components in the average production machining cycle is affected by cutting speed (two correct answers):

A)average tool change time per piece
B)part loading and unloading time
C)setup time for the machine tool
D)time the tool is engaged in cutting

Question 12

Which cutting speed is always lower for a given machining operation:

A)cutting speed for maximum production rate
B)cutting speed for minimum cost

Question 13

A high tooling cost and/or tool change time will tend to

A)decrease
B)have no effect on
C)increase the cutting speed for minimum cost