Slide 1

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 2

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 3

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 4

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 5

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 6

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 7

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 8

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 9

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 10

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 11

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 12

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 13

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 14

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 15

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 16

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 17

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.


Slide 18

10

Tolerancing

• Define terms related to tolerancing.
• Explain how tolerances are expressed on a
drawing.
• Identify tolerance values for dimensions on the
drawing, regardless of the tolerancing expression.
• Compare customary inch tolerance classes with
metric tolerance classes.
• Calculate tolerances or limits for mating parts based
on maximum material conditions and allowance.

Permission granted to reproduce for educational use only.

Tolerancing Defined
• Tolerance is the total amount by which a
dimension can vary
• Expressed as:
– Bilateral
– Unilateral
– Limits

Permission granted to reproduce for educational use only.

Tolerancing Defined
• In each of these examples, the tolerance is .008

Permission granted to reproduce for educational use only.

Tolerancing Applied
• Tolerances can be applied to both location and
size dimensions

Permission granted to reproduce for educational use only.

Tolerancing Concepts
• Basic hole system: system for calculating the limits
of a hole-shaft relationship
• Maximum material condition: condition of a feature
wherein the most material is present
• Least material condition: condition of a feature
wherein the least material is present
• Allowance: tightest fit of two parts calculated by
comparing maximum material conditions

Permission granted to reproduce for educational use only.

Datum Identification
• A datum may be represented by a surface, center
plane, or an axis

Permission granted to reproduce for educational use only.

Dimension Origin Symbol

Permission granted to reproduce for educational use only.

American Standard Tolerances
• Classifications for ASME fits:
–
–
–
–
–

Running or sliding clearance fits (RC)
Locational clearance fits (LC)
Transitional clearance or interference fits (LT)
Locational interference fits (LN)
Force or shrink fits (FN)

Permission granted to reproduce for educational use only.

Metric Tolerances and Fits
• Classifications for metric fits:

Permission granted to reproduce for educational use only.

Permission granted to reproduce for educational use only.

• What is the difference between tolerance and
limits?

Tolerance is the total amount by which a
dimension can vary. Limits are the extreme
maximum and minimum dimensions allowed by
the tolerance.

Permission granted to reproduce for educational use only.

• What is the difference between a unilateral
tolerance and a bilateral tolerance?

A unilateral tolerance varies from the
dimensional value in one direction only
(either plus or minus). A bidirectional
tolerance varies from the dimensional value
in both plus and minus directions.

Permission granted to reproduce for educational use only.

• What are the two basic ways in which tolerances
are expressed on the dimensions of a drawing?

Plus-and-minus dimensioning and limit
dimensioning (may also be expressed as a
general tolerance in the tolerance block).

Permission granted to reproduce for educational use only.

• If a dimension is 2.235 .005, what is the tolerance?

.010

Permission granted to reproduce for educational use only.

• How does the metric system of tolerances and fits
differ from the American system?

The concept is the same between the two
systems, but different notation is used.

Permission granted to reproduce for educational use only.

• If a hole is  .187+.002/–.000 and a shaft is
 .187+.000/–.003, what is the allowance?

.000

Permission granted to reproduce for educational use only.