# Measuring Flashcards

1
Q

Describe nominal size

A

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

2
Q

Describe actual size

A

The measured size of a component

3
Q

Describe basic size

A

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

4
Q

What are the 3 fit types? Describe?

A

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

5
Q

What is tolerance?

A

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

6
Q

Describe limit of size:

A

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

7
Q

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

A

Maximum metal condition

8
Q

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

A

Least metal condition

9
Q

What is unilateral tolerance?

A

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

10
Q

What is bilateral tolerance?

A

Bilateral tolerance is in both directions from basic size.

11
Q

Describe limits of dimension

A

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

12
Q

What is allowance?

A

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

13
Q

Describe hole basis system?

A

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

14
Q

Describe shaft basis system:

A

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

15
Q

What factors affect design tolerances?

A

Temperature
Lubrication
Metal type

16
Q

What is linear expansion?

A

The measurement of expansion in one direction.

17
Q

What is coefficient expansion?

A

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

18
Q

what is the formula for calculating change in length?

A

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”

19
Q

What is the standard measuring temperature?

A

20C or 68F