Measuring

Question 1

Describe nominal size

Answer 1

Nominal size refers to an imperial standard size, which is used for the purpose of general identification

.9975 1.000
Shaft Bore

+0000. +.002
-.0012. -.000

Question 2

Describe actual size

Answer 2

The measured size of a component

Question 3

Describe basic size

Answer 3

Basic size is the theoretical size to which the tolerance is applied.

Question 4

What are the 3 fit types? Describe?

Answer 4

Interference fit: which have a negative allowance and the total tolerances do not exceed the allowance

Clearance fit: which have positive allowances

Transition fits: which have negative allowances, but the total tolerances exceed the allowance

Question 5

What is tolerance?

Answer 5

Tolerance is the total amount of variation permitted in the size of duplicate parts.

Question 6

Describe limit of size:

Answer 6

Limit of size are the largest(upper limit) size and smallest(lowest limit) size a part can be and still be acceptable.

Question 7

What condition is used when you have the smallest hole with the largest shaft?

Answer 7

Maximum metal condition

Question 8

What condition is it when you have the largest hole with the smallest shaft?

Answer 8

Least metal condition

Question 9

What is unilateral tolerance?

Answer 9

Unilateral tolerance is one direction only from its basic size, there is no variation in the other direction.

Question 10

What is bilateral tolerance?

Answer 10

Bilateral tolerance is in both directions from basic size.

Question 11

Describe limits of dimension

Answer 11

Only the maximum and minimum dimensions of the parts are specified.

Question 12

What is allowance?

Answer 12

Allowance is the intentional difference between two mating parts.

Positive allowance the hole is bigger then the shaft.

Negative allowance the the hole is smaller then the shaft

Question 13

Describe hole basis system?

Answer 13

The hole is considered the master size and the shaft component is manufactured to the tolerance to produce the desired fit.

Question 14

Describe shaft basis system:

Answer 14

The shaft is considered the master size and the hole component is manufactured to the tolerance to produce the desired fit.

Question 15

What factors affect design tolerances?

Answer 15

Load
Temperature
Lubrication
Metal type

Question 16

What is linear expansion?

Answer 16

The measurement of expansion in one direction.

Question 17

What is coefficient expansion?

Answer 17

The set rate of expansion for every degree of temperature change.

Question 18

what is the formula for calculating change in length?

Answer 18

Original length x temperature change x coefficient of expansion

Example

My piece of steel is 36”long. is 68 degrees to start and heat to 300 degrees. What is my temperature change? 300-68=232 degree temp change.

36x232x.0000114=.0952

36+.0952=36.0952”

Question 19

What is the standard measuring temperature?

Answer 19

20C or 68F