Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Millwright Block 2 (harmonized) NS > Tolerances And Fits > Flashcards

Tolerances And Fits Flashcards

1
Q

What is basic hole size in terms of tolerance?

A

The hole is your size, your shaft is what is adjusted to mate parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe basic shaft size in terms of tolerances

A

Your shaft is your “basic size” and your hole is the part being adjusted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does unilateral tolerance mean?

A

That all tolerances and dimensions are applied in only 1 direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does bilateral tolerance mean?

A

That the tolerances and dimensions are applied in both directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is a class 3 fit?

A

Interference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What causes fatigue failure?

A

Repeated stress has work hardened it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the main characteristic of stainless steel?

A

Corrosion resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the approximate percent of medium carbon steel?

A

.30-.50 percent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What form of tolerance does +/- 0.002 represent?

A

Bilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What part of a dimension is the total permissible variation in its size?

A

Tolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Twisting forces put what sort of stress on a key?

A

Shear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where should a millwright place the bearing on a shaft if he has a choice?

A

As close to the loaded components as possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the best tool for determining radial runout?

A

Dial indicator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Sliding fit is an example of what allowance?

A

Positive allowance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Prussian blue used for?

A

Identifying contact patterns for fitting and adjusting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What will improve with carful attention to surface finish, large fillets, runout keys, sharp edges, and closer diameter reduction ratios?

A

Fewer stress fractures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is tolerance?

A

Total permissible deviation of a dimension on a part

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the difference between the max and min limits of size called?

A

Tolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two systems for applying tolerances to the dimensions of a mating part called?

A

Basic hole
Basic shaft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

“The design size of the hole is basic the allowance is on the shaft” is what tolerance system?

A

Basic hole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the excess material on a part called?

A

Allowance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define allowance

A

Excess material on a part

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

“The design size of the shaft is the basic size and the allowance is in the bore of the mating part” is what tolerance system?

A

Basic shaft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is unilateral tolerance?

A

When all tolerance for the drawing is applied in one direction only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is bilateral tolerance?

A

When the tolerance for the drawing dimensions are applied in both directions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

When the drawing tolerance dimensions go in both directions what is it called?

A

Bilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

When the drawing dimension tolerances go in 1 direction what is it called?

A

Unilateral tolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is another word for allowance?

A

Fit

29
Q

What does “positive allowance” refer to?

A

The minimum clearance between mating parts.

30
Q

What does “negative allowance” refer to?

A

The maximum interference between parts

31
Q

The maximum interference between parts is called what?

A

Negative allowance

32
Q

The minimum clearance between parts is called what?

A

Positive allowance

33
Q

What is the degree of fit?

A

Result specifying a tolerance to each mating part

34
Q

What are the two basic types of fit?

A

Clearance
Interference

35
Q

What is clearance fit?

A

When mating parts maintain some clearance between them

36
Q

What is interference fit?

A

When there is some resistance between mating parts

37
Q

What are the 5 main classes of fit?

A

Running/sliding clearance fit
Locational clearance fit
Transition fit
Locational interference fit
Force/shrink fit

38
Q

What class of fit provides room between mating parts for lubrication?

A

Running/sliding fit

39
Q

What does running fit refer to?

A

Rotating parts

40
Q

What does sliding fit refer to?

A

To parts the slide on each other

41
Q

In sliding fit what does the clearance refer to?

A

The surface above

42
Q

How is a gib used with a dove tail?

A

To adjust the clearance between the mating parts

43
Q

Where is locational clearance fit used?

A

Normally stationary parts which can be freely assembled or disassembled

44
Q

Where is transition fits used?

A

On mating parts

45
Q

What is transition fit?

A

When the tolerance on mating parts partially overlaps so either a clearance or interference fit can occur

46
Q

Where is locational interference fits used?

A

Situations where accurate location and rigid alignment is of utmost importance

47
Q

What is locational fit NOT meant to do?

A

Transmit frictional loads from one part to another

48
Q

What is force/shrink fits?

A

When the tolerance of mating parts fully overlaps causing an interference fit

49
Q

How is the method of assembly determined? (3)

A

By the amount of interference
Availability of equipment
Size of the parts to be assembled

50
Q

What are the three common methods of assembling mating parts?

A

Forced fitting
Shrink fitting
Expansion fitting

51
Q

What is forced fitting?

A

One part is pressed onto another part

52
Q

What is shrink fitting?

A

The hub is heated to expand to allow it to be easily assembled onto the shaft

53
Q

What is expansion fitting?

A

The shaft is cooled so the part may be easily slipped onto the shaft

54
Q

What is the best method for force fitting?

A

Hydraulic press with a manual lever preferably

55
Q

What are the heat sources that can be used for shrink fitting? (6)

A

Hot water/oil bath
Steam
Torch
Furnace
Electric resistance heating
Electric induction heating

56
Q

What are the 4 methods for expansion fitting

A

Industrial refrigerator
Liquid air
Liquid nitrogen
Alcohol/dry ice

57
Q

What are the 4 main types of presses?

A

Fixed in place hydraulic
Mechanical arbor
Free standing hydraulic
Portable hydraulic press

58
Q

What are manual pullers used for?

A

Light pulling jobs that don’t require large forces

59
Q

What are the 3 situations where a manual puller would be used

A

Pulling a component off a shaft
Pulling a component out of a hole
Pulling a shaft out of a component

60
Q

What are the two most common styles of manual pullers?

A

Jaw
Rod

61
Q

How would you choose a manual puller?

A

The diameter of the adjusting screw should be at least 1/2 the size of the shaft

62
Q

In a hydraulic application how would you choose a puller?

A

A puller that can withstand a force exerted in tons 7-10x the diameter of the shaft in inches

63
Q

A minimum bore diameter and maximum shaft diameter is what fit?

A

Interference

64
Q

A maximum bore diameter and minimum shaft diameter is what fit?

A

Clearance fit

65
Q

Each group of fits breaks down into grades. What are the grades?

A

RC 1 - RC 9

66
Q

What is a RC 1 fit?

A

Close sliding fit

67
Q

What is RC 9 fit?

A

Loose running fit

68
Q

What type of allowance is sliding fit?

A

Positive

Millwright Block 2 (harmonized) NS (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions