21917046 machining symbols

96
Based on the ASME Y14.5M Based on the ASME Y14.5M- 1994 Dimensioning and 1994 Dimensioning and Tolerancing Standard Tolerancing Standard DIMENSIONAL ENGINEERING

Upload: askaralik8

Post on 27-Jun-2015

186 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: 21917046 Machining Symbols

Based on the ASME Y14.5MBased on the ASME Y14.5M--

1994 Dimensioning and 1994 Dimensioning and

Tolerancing StandardTolerancing Standard

DIMENSIONAL

ENGINEERING

Page 2: 21917046 Machining Symbols

Tolerances

of Form

Straightness Flatness

Circularity Cylindricity

(ASME Y14.5M-1994, 6.4.1)

(ASME Y14.5M-1994, 6.4.3)

(ASME Y14.5M-1994, 6.4.2)

(ASME Y14.5M-1994, 6.4.4)

Page 3: 21917046 Machining Symbols

Extreme Variations of Form

Allowed By Size Tolerance25.1 25

25

(MMC)

25.1

(LMC)

25.1

(LMC)

25

(MMC)

25.1

(LMC)

MMC Perfect

Form Boundary

Internal Feature of Size

Page 4: 21917046 Machining Symbols

Extreme Variations of Form

Allowed By Size Tolerance25 24.9

25

(MMC)24.9

(LMC)

24.9

(LMC)

MMC Perfect

Form Boundary25

(MMC)

24.9

(LMC)

External Feature of Size

Page 5: 21917046 Machining Symbols

25 +/-0.25

0.1 Tolerance

0.5 Tolerance

Straightness is the condition where an element of a

surface or an axis is a straight line

Straightness (Flat Surfaces)

0.5 0.1

Page 6: 21917046 Machining Symbols

Straightness (Flat Surfaces)

24.75 min25.25 max

0.5 Tolerance Zone

0.1 Tolerance Zone

The straightness tolerance is applied in the view where the

elements to be controlled are represented by a straight line

In this example each line element of the surface must lie

within a tolerance zone defined by two parallel lines

separated by the specified tolerance value applied to each

view. All points on the surface must lie within the limits of

size and the applicable straightness limit.

Page 7: 21917046 Machining Symbols

Straightness (Surface Elements)

MMC

0.1 Tolerance Zone

0.1

MMC

0.1 Tolerance Zone

MMC

0.1 Tolerance Zone

In this example each longitudinal element of the surface must

lie within a tolerance zone defined by two parallel lines

separated by the specified tolerance value. The feature must

be within the limits of size and the boundary of perfect form at

MMC. Any barreling or waisting of the feature must not

exceed the size limits of the feature.

Page 8: 21917046 Machining Symbols

Straightness (RFS)Straightness (RFS)Straightness (RFS)Straightness (RFS)

0.1

Outer Boundary (Max)

MMC

0.1 Diameter

Tolerance Zone

Outer Boundary = Actual Feature Size + Straightness ToleranceOuter Boundary = Actual Feature Size + Straightness ToleranceOuter Boundary = Actual Feature Size + Straightness ToleranceOuter Boundary = Actual Feature Size + Straightness Tolerance

In this example the derived median line of the feature’s actual local size must lie within a tolerance zone defined by a cylinder whose diameter is equal to the specified tolerance value regardless of the feature size. Each circular element of the feature must be within the specified limits of size. However, the boundary of perfect form at MMC can be violated up to the maximum outer boundary or virtual condition diameter.

Page 9: 21917046 Machining Symbols

Straightness (MMC)15

14.85

15.1 Virtual Condition

15

(MMC)

0.1 Diameter

Tolerance Zone

15.1 Virtual Condition

14.85

(LMC)

0.25 Diameter

Tolerance Zone

Virtual Condition = MMC Feature Size + Straightness Tolerance

In this example the derived median line of the feature’s actual local size

must lie within a tolerance zone defined by a cylinder whose diameter is

equal to the specified tolerance value at MMC. As each circular element

of the feature departs from MMC, the diameter of the tolerance cylinder

is allowed to increase by an amount equal to the departure from the local

MMC size. Each circular element of the feature must be within the

specified limits of size. However, the boundary of perfect form at MMC

can be violated up to the virtual condition diameter.

0.1 M

Page 10: 21917046 Machining Symbols

Flatness

Flatness is the condition of a surface having all elements in

one plane. Flatness must fall within the limits of size. The

flatness tolerance must be less than the size tolerance.

25 +/-0.25

24.75 min25.25 max

0.1

0.1 Tolerance Zone

0.1 Tolerance Zone

In this example the entire surface must lie within a tolerance

zone defined by two parallel planes separated by the specified

tolerance value. All points on the surface must lie within the

limits of size and the flatness limit.

Page 11: 21917046 Machining Symbols

Circularity is the condition of a surface where all points of the

surface intersected by any plane perpendicular to a common

axis are equidistant from that axis. The circularity tolerance

must be less than the size tolerance

90

90

0.1

0.1 Wide Tolerance Zone

Circularity (Roundness)

In this example each circular element of the surface must lie within a

tolerance zone defined by two concentric circles separated by the

specified tolerance value. All points on the surface must lie within the

limits of size and the circularity limit.

0.1

Page 12: 21917046 Machining Symbols

Cylindricity

Cylindricity is the condition of a surface of revolution in which

all points are equidistant from a common axis. Cylindricity is a

composite control of form which includes circularity

(roundness), straightness, and taper of a cylindrical feature.

0.1 Tolerance Zone

MMC

0.1

In this example the entire surface must lie within a tolerance zone

defined by two concentric cylinders separated by the specified

tolerance value. All points on the surface must lie within the limits of

size and the cylindricity limit.

Page 13: 21917046 Machining Symbols

____________ and ___________ are individual line or circular

element (2-D) controls.

Form Control Quiz

The four form controls are ____________, ________,

___________, and ____________.

Rule #1 states that unless otherwise specified a feature of

size must have ____________at MMC.

________ and ____________are surface (3-D) controls.

Circularity can be applied to both ________and _______ cylindrical

parts.

1.

2.

3.

4.

5.

Form controls require a datum reference.

Form controls do not directly control a feature’s size.

A feature’s form tolerance must be less than it’s sizetolerance.

Flatness controls the orientation of a feature.

Size limits implicitly control a feature’s form.

6.

7.

8.

9.

10.

Questions #1-5 Fill in blanks (choose from below)

straightness

flatness

circularity

cylindricity

perfect form

straight tapered profile

true position

angularity

Answer questions #6-10 True or False

Page 14: 21917046 Machining Symbols

Tolerances of

Orientation

Angularity

Perpendicularity

Parallelism

(ASME Y14.5M-1994 ,6.6.2)

(ASME Y14.5M-1994 ,6.6.4)

(ASME Y14.5M-1994 ,6.6.3)

Page 15: 21917046 Machining Symbols

Angularity (Feature Surface to Datum Surface)

Angularity is the condition of the planar feature surface at a

specified angle (other than 90 degrees) to the datum

reference plane, within the specified tolerance zone.

A

20 +/-0.5

30 o

A

19.5 min

0.3 Wide

Tolerance

Zone

30 o

A

20.5 max

0.3 Wide

Tolerance

Zone

30 o

The tolerance zone in this example is defined

by two parallel planes oriented at the

specified angle to the datum reference plane.

0.3 A

Page 16: 21917046 Machining Symbols

Angularity is the condition of the feature axis at a specified

angle (other than 90 degrees) to the datum reference plane,

within the specified tolerance zone.

A

0.3 A

A

60 o

The tolerance zone in this example is defined by a

cylinder equal to the length of the feature, oriented

at the specified angle to the datum reference plane.

0.3 Circular

Tolerance Zone

0.3 Circular

Tolerance Zone

Angularity (Feature Axis to Datum Surface)

NOTE: Tolerance applies

to feature at RFS

Page 17: 21917046 Machining Symbols

0.3 Circular

Tolerance Zone

NOTE: Tolerance

applies to feature

at RFS

Angularity is the condition of the feature axis at a specified

angle (other than 90 degrees) to the datum reference axis,

within the specified tolerance zone.

0.3 Circular

Tolerance Zone

A

Datum Axis A

Angularity (Feature Axis to Datum Axis)

The tolerance zone in this example is defined by a

cylinder equal to the length of the feature, oriented

at the specified angle to the datum reference axis.

NOTE: Feature axis must lie

within tolerance zone cylinder0.3 A

o45

Page 18: 21917046 Machining Symbols

0.3 A

A

0.3 Wide

Tolerance Zone

A A

Perpendicularity is the condition of the planar feature

surface at a right angle to the datum reference plane, within

the specified tolerance zone.

Perpendicularity (Feature Surface to Datum Surface)

0.3 Wide

Tolerance Zone

The tolerance zone in this example is

defined by two parallel planes oriented

perpendicular to the datum reference

plane.

Page 19: 21917046 Machining Symbols

C

Perpendicularity is the condition of the feature axis at a right

angle to the datum reference plane, within the specified

tolerance zone.

Perpendicularity (Feature Axis to Datum Surface)

0.3 C

0.3 Circular

Tolerance Zone

0.3 Diameter

Tolerance Zone

0.3 Circular

Tolerance Zone

NOTE: Tolerance applies

to feature at RFS

The tolerance zone in this example is

defined by a cylinder equal to the length of

the feature, oriented perpendicular to the

datum reference plane.

Page 20: 21917046 Machining Symbols

Perpendicularity (Feature Axis to Datum Axis)

NOTE: Tolerance applies

to feature at RFS

The tolerance zone in this example is

defined by two parallel planes oriented

perpendicular to the datum reference axis.

Perpendicularity is the condition of the feature axis at a right

angle to the datum reference axis, within the specified

tolerance zone.

0.3 Wide

Tolerance Zone

A

Datum Axis A

0.3 A

Page 21: 21917046 Machining Symbols

0.3 A

A

25 +/-0.5

25.5 max

0.3 Wide Tolerance Zone

A

24.5 min

0.3 Wide Tolerance Zone

A

Parallelism is the condition of the planar feature surface

equidistant at all points from the datum reference plane,

within the specified tolerance zone.

Parallelism (Feature Surface to Datum Surface)

The tolerance zone in this example

is defined by two parallel planes

oriented parallel to the datum

reference plane.

Page 22: 21917046 Machining Symbols

A

0.3 Wide

Tolerance Zone

Parallelism (Feature Axis to Datum Surface)

0.3 A

A

NOTE: The specified tolerance

does not apply to the orientation

of the feature axis in this direction

Parallelism is the condition of the feature axis equidistant

along its length from the datum reference plane, within the

specified tolerance zone.

The tolerance zone in this example

is defined by two parallel planes

oriented parallel to the datum

reference plane.

NOTE: Tolerance applies

to feature at RFS

Page 23: 21917046 Machining Symbols

A

B

Parallelism (Feature Axis to Datum Surfaces)

A

B

0.3 Circular

Tolerance Zone

0.3 Circular

Tolerance Zone

0.3 Circular

Tolerance Zone

Parallelism is the condition of the feature axis equidistant

along its length from the two datum reference planes, within

the specified tolerance zone.

The tolerance zone in this example is

defined by a cylinder equal to the

length of the feature, oriented parallel

to the datum reference planes.

NOTE: Tolerance applies

to feature at RFS

0.3 A B

Page 24: 21917046 Machining Symbols

Parallelism (Feature Axis to Datum Axis)

Parallelism is the condition of the feature axis equidistant along

its length from the datum reference axis, within the specified

tolerance zone.

A

0.1 A

0.1 Circular

Tolerance Zone

0.1 Circular

Tolerance Zone

Datum Axis A

The tolerance zone in this example is

defined by a cylinder equal to the

length of the feature, oriented

parallel to the datum reference axis.

NOTE: Tolerance applies

to feature at RFS

Page 25: 21917046 Machining Symbols

Orientation Control Quiz

The three orientation controls are __________, ___________,

and ________________.

1.

2.

3.

4.

5.

A _______________ is always required when applying any of

the orientation controls.

________________ is the appropriate geometric tolerance when

controlling the orientation of a feature at right angles to a datumreference.

Orientation tolerances indirectly control a feature’s form.

Mathematically all three orientation tolerances are _________.

Orientation tolerances do not control the ________ of a feature.

6.

Orientation tolerance zones can be cylindrical.

Parallelism tolerances do not apply to features of size.

To apply an angularity tolerance the desired angle mustbe indicated as a basic dimension.

7.

8.

9.

10.

To apply a perpendicularity tolerance the desired anglemust be indicated as a basic dimension.

Questions #1-5 Fill in blanks (choose from below)

angularity

perpendicularity

parallelism

datum reference

identical

location

profile

datum feature

datum target

Answer questions #6-10 True or False

Page 26: 21917046 Machining Symbols

Tolerances of Runout

Circular Runout

(ASME Y14.5M-1994, 6.7.1.2.1)

Total Runout

(ASME Y14.5M-1994 ,6.7.1.2.2)

Page 27: 21917046 Machining Symbols

Datum feature

Datum axis (established

from datum feature

Angled surfaces

constructed around

a datum axis

External surfaces

constructed around

a datum axis

Internal surfaces

constructed around a

datum axis

Surfaces constructed

perpendicular to a

datum axis

Features Applicable

to Runout Tolerancing

Page 28: 21917046 Machining Symbols

0+ -

Full Indicator

Movement

Maximum Minimum

Total

Tolerance

Maximum

ReadingMinimum Reading

Full Part

Rotation

Measuring position #1 (circular element #1)

Circular Runout

When measuring circular runout, the indicator must be reset to zero at each measuring position

along the feature surface. Each individual circular element of the surface is independently

allowed the full specified tolerance. In this example, circular runout can be used to detect 2-

dimensional wobble (orientation) and waviness (form), but not 3-dimensional characteristics such as surface profile (overall form) or surface wobble (overall orientation).

Measuring position #2

(circular element #2)

Circular runout can only be applied on an

RFS basis and cannot be modified to

MMC or LMC.

Page 29: 21917046 Machining Symbols

o360 Part

Rotation

50 +/- 2o o

As Shownon Drawing

Means This:

Datum axis A

Single circular

element

Circular Runout(Angled Surface to Datum Axis)

0.75 A

A

50 +/-0.25

0+-

NOTE: Circular runout in this example only controls the 2-dimensional circular elements

(circularity and coaxiality) of the angled feature surface not the entire angled feature surface

Full Indicator

Movement( )

The tolerance zone for any individual circular element is equal to the total allowable movement of a dial indicator fixed in a position normal to the true geometric shape of the feature surface when the part is rotated 360 degrees about the datum axis. The tolerance limit is applied independently to each individual measuring position along the feature surface.

Allowable indicator

reading = 0.75 max.

When measuring circular

runout, the indicator must

be reset when repositioned

along the feature surface.

Collet or Chuck

Page 30: 21917046 Machining Symbols

As Shownon Drawing

50 +/-0.25

0.75 A

Circular Runout(Surface Perpendicular to Datum Axis)

o360 Part

Rotation

0+-

Datum axis A

Single circular

element

NOTE: Circular runout in this example will

only control variation in the 2-dimensional circular elements of the planar surface (wobble and waviness) not the entire feature surface

The tolerance zone for any individual circular element is equal to the total allowable movement of a dial indicator fixed in a position normal to the true geometric shape of the feature surface when the part is rotated 360 degrees about the datum axis. The tolerance limit is applied independently to each individual measuring position along the feature surface.

Means This:

Allowable indicator

reading = 0.75 max.

When measuring circular runout, the indicator must

be reset when repositioned along the feature surface.

A

Page 31: 21917046 Machining Symbols

0+ -

Allowable indicator

reading = 0.75 max.

Single circular element

o360 Part

Rotation

Means This:

As Shownon Drawing

50 +/-0.25

0.75 A

Datum axis A

When measuring circular runout,

the indicator must be reset when

repositioned along the feature

surface.

Circular Runout(Surface Coaxial to Datum Axis)

The tolerance zone for any individual circular element is equal to the total allowable movement of a dial indicator fixed in a position normal to the true geometric shape of the feature surface when the part is rotated 360 degrees about the datum axis. The tolerance limit is applied independently to each individual measuring position along the feature surface.

NOTE: Circular runout in this example will only control variation in the 2-dimensional

circular elements of the surface (circularity and coaxiality) not the entire feature surface

A

Page 32: 21917046 Machining Symbols

0+ -

Allowable indicator

reading = 0.75 max.

Single circular element

o360 Part

Rotation

Means This:

As Shownon Drawing

0.75 A-B

Datum axis A-B

When measuring circular runout,

the indicator must be reset when

repositioned along the feature

surface.

Circular Runout(Surface Coaxial to Datum Axis)

The tolerance zone for any individual circular element is equal to the total allowable movement of a dial indicator fixed in a position normal to the true geometric shape of the feature surface when the part is rotated 360 degrees about the datum axis. The tolerance limit is applied independently to each individual measuring position along the feature surface.

NOTE: Circular runout in this example will only control variation in the 2-dimensional

circular elements of the surface (circularity and coaxiality) not the entire feature surface

Machine

center

Machine

center

BA

Page 33: 21917046 Machining Symbols

As Shownon Drawing

50 +/-0.25

Circular Runout(Surface Related to Datum Surface and Axis)

o360 Part

Rotation

0+ -

Datum axis B

Single circular element

The tolerance zone for any individual circular element is equal to the total allowable movement of a dial indicator fixed in a position normal to the true geometric shape of the feature surface when the part is located against the datum surface and rotated 360 degrees about the datum axis. The tolerance limit is applied independently to each individual measuring position along the feature surface.

Means This:

A

Allowable indicator

reading = 0.75 max.

When measuring circular runout,

the indicator must be reset when

repositioned along the feature

surface.

Collet or Chuck

Stop collar

0.75 A B

Datum plane A

B

Page 34: 21917046 Machining Symbols

0+

Full Indicator

Movement

Total

Tolerance

Maximum

ReadingMinimum Reading

Full Part

Rotation

-

0+ -

Total Runout

Maximum Minimum

When measuring total runout, the indicator is moved in a straight line along the feature surface

while the part is rotated about the datum axis. It is also acceptable to measure total runout by evaluating an appropriate number of individual circular elements along the surface while the part

is rotated about the datum axis. Because the tolerance value is applied to the entire surface, the

indicator must not be reset to zero when moved to each measuring position. In this example,

total runout can be used to measure surface profile (overall form) and surface wobble (overall

orientation).

Indicator

Path

Total runout can only be applied on an

RFS basis and cannot be modified to

MMC or LMC.

Page 35: 21917046 Machining Symbols

Full Part

Rotation

50 +/- 2o o

As Shownon Drawing

A

50 +/-0.25

0.75 A

Means This:

Datum axis A

0+-

The tolerance zone for the entire angled surface is equal to the total allowable movement of a dial indicator positioned normal to the true geometric shape of the feature surface when the part is rotated about the datum axis and the indicator is moved along the entire length of the feature surface.0

+-

NOTE: Unlike circular runout, the use of total runoutwill provide 3-dimensional composite control of the cumulative variations of circularity, coaxiality,

angularity, taper and profile of the angled surface

Total Runout(Angled Surface to Datum Axis)

Collet or Chuck

When measuring total runout, the

indicator must not be reset when

repositioned along the feature

surface.

(applies to the entire feature surface)Allowable indicator reading = 0.75 max.

Page 36: 21917046 Machining Symbols

0+-

Total Runout(Surface Perpendicular to Datum Axis)

As Shownon Drawing

A

50 +/-0.25

0.75 A

35

10

0+-

Datum axis AFull Part Rotation

35

10

Means This:

NOTE: The use of total runout in this example will provide composite control of the cumulative variations of perpendicularity (wobble) and

flatness (concavity or convexity) of the feature surface.

The tolerance zone for the portion of the feature surface indicated is equal to the total allowable movement of a dial indicator positioned normal to the true geometric shape of the feature surface when the part is rotated about the datum axis and the indicator is moved along the portion of the feature surface within the area described by the basic dimensions.

When measuring total runout, the indicator

must not be reset when repositioned along the

feature surface.

(applies to portion of feature surface indicated)Allowable indicator reading = 0.75 max.

Page 37: 21917046 Machining Symbols

Runout Control Quiz

Answer questions #1-12 True or False

Total runout is a 2-dimensional control.1.

Runout tolerances are used on rotating parts.

Total runout tolerances should be applied at MMC.

Runout tolerances can be applied to surfaces at rightangles to the datum reference.

2.

3.

4.

5.

Circular runout tolerances apply to single elements .

6. Circular runout tolerances are used to control an entirefeature surface.

Runout tolerances always require a datum reference.7.

Circular runout and total runout both control axis to surface relationships.

8.

Circular runout can be applied to control taper of a part.9.

Total runout tolerances are an appropriate way to limit “wobble” of a rotating surface.

10.

Runout tolerances are used to control a feature’s size.11.

Total runout can control circularity, straightness, taper,coaxiality, angularity and any other surface variation.

12.

Page 38: 21917046 Machining Symbols

Tolerances

of Profile

Profile of a Line

Profile of a Surface

(ASME Y14.5M-1994, 6.5.2b)

(ASME Y14.5M-1994, 6.5.2a)

Page 39: 21917046 Machining Symbols

18 Max

Profile of a Line

2 Wide Size

Tolerance Zone

1 A B C

A

17 +/- 1

1 Wide Profile

Tolerance Zone

C

A1

20 X 20

A2

20 X 20

A3

20 X 20

B

The profile tolerance zone in this example is defined by two

parallel lines oriented with respect to the datum reference

frame. The profile tolerance zone is free to float within the

larger size tolerance and applies only to the form and

orientation of any individual line element along the entire

surface.

Profile of a Line is a two-dimensional tolerance that can be applied to a

part feature in situations where the control of the entire feature surface as

a single entity is not required or desired. The tolerance applies to the line

element of the surface at each individual cross section indicated on the

drawing.

16 Min.

Page 40: 21917046 Machining Symbols

Profile of a Surface is a three-dimensional tolerance that can be applied

to a part feature in situations where the control of the entire feature

surface as a single entity is desired. The tolerance applies to the entire

surface and can be used to control size, location, form and/or orientation

of a feature surface.

Profile of a Surface

2 Wide Tolerance Zone

Size, Form and Orientation

A

A1

20 X 20

A2

20 X 20

A3

20 X 20

C 2 A B C

23.5

23.5Nominal

Location

The profile tolerance zone in this example is defined by two parallel

planes oriented with respect to the datum reference frame. The profile

tolerance zone is located and aligned in a way that enables the part

surface to vary equally about the true profile of the feature.

B

Page 41: 21917046 Machining Symbols

Profile of a Surface

A1

20 X 20

A2

20 X 20

A3

20 X 20

B

C

50

B

C

50

1 Wide Total

Tolerance Zone

(Bilateral Tolerance)

The tolerance zone in this example is defined by two parallel planes

oriented with respect to the datum reference frame. The profile tolerance

zone is located and aligned in a way that enables the part surface to

vary equally about the true profile of the trim.

1 A B C

Nominal Location

0.5 Inboard

0.5 Outboard

Profile of a Surface when applied to trim edges of sheet metal parts will control

the location, form and orientation of the entire trimmed surface. When a

bilateral value is specified, the tolerance zone allows the trim edge variation

and/or locational error to be on both sides of the true profile. The tolerance

applies to the entire edge surface.

Page 42: 21917046 Machining Symbols

Profile of a Surface

A1

20 X 20

A2

20 X 20

A3

20 X 20

B

C

50

B

C

50

0.5 Wide Total

Tolerance Zone

(Unilateral Tolerance)

Profile of a Surface when applied to trim edges of sheet metal parts will control

the location, form and orientation of the entire trimmed surface. When a

unilateral value is specified, the tolerance zone limits the trim edge variation

and/or locational error to one side of the true profile. The tolerance applies to

the entire edge surface.

The tolerance zone in this example is defined by two parallel planes

oriented with respect to the datum reference frame. The profile tolerance

zone is located and aligned in a way that allows the trim surface to vary

from the true profile only in the inboard direction.

0.5 A B C

Nominal Location

Page 43: 21917046 Machining Symbols

Profile of a Surface

A1

20 X 20

A2

20 X 20

A3

20 X 20

B

C

50

1.2 A B C

B

C

50

0.5 Inboard

0.7 Outboard

1.2 Wide Total

Tolerance Zone

(Unequal Bilateral Tolerance)

Profile of a Surface when applied to trim edges of sheet metal parts will control

the location, form and orientation of the entire trimmed surface. Typically when

unequal values are specified, the tolerance zone will represent the actual

measured trim edge variation and/or locational error. The tolerance applies to

the entire edge surface.

The tolerance zone in this example is defined by two parallel planes

oriented with respect to the datum reference frame. The profile tolerance

zone is located and aligned in a way that enables the part surface to

vary from the true profile more in one direction (outboard) than in the

other (inboard).

0.5

Nominal Location

Page 44: 21917046 Machining Symbols

A

25

A0.5

0.1

25.2524.75

0.1 Wide Tolerance Zone

A

Composite Profile of Two Coplanar

Surfaces w/o Orientation Refinement

Profile of a Surface

Form Only

Location & Orientation

Page 45: 21917046 Machining Symbols

0.1 Wide Tolerance Zone

0.1 Wide Tolerance Zone

25.25

24.75

A

A

A

25

A0.5

A0.1 Form & Orientation

Composite Profile of Two Coplanar

Surfaces With Orientation Refinement

Profile of a Surface

Location

Page 46: 21917046 Machining Symbols

6.

Profile Control Quiz

Profile tolerances always require a datum reference.

Answer questions #1-13 True or False

1.

Profile of a surface tolerance is a 2-dimensional control.

Profile of a line tolerances should be applied at MMC.

Profile tolerances can be applied to features of size.

2.

3.

4.

5.

Profile of a surface tolerance should be used to controltrim edges on sheet metal parts.

Profile tolerances can be combined with other geometric controls such as flatness to control a feature.

Profile of a line tolerances apply to an entire surface.7.

Profile of a line controls apply to individual line elements.8.

Profile tolerances only control the location of a surface.9.

Composite profile controls should be avoided becausethey are more restrictive and very difficult to check.

10.

Profile tolerances can be applied either bilateral orunilateral to a feature.

11.

Profile tolerances can be applied in both freestate andrestrained datum conditions.

12.

Tolerances shown in the lower segment of a compositeprofile feature control frame control the location of afeature to the specified datums.

13.

Page 47: 21917046 Machining Symbols

In composite profile applications, the tolerance shown in the upper

segment of the feature control frame applies only to the ________ of

the feature.

Profile Control Quiz

The two types of profile tolerances are _________________,

and ____________________.1.

2.

3.

4.

5.

Profile tolerances can be used to control the ________, ____,

___________ , and sometimes size of a feature.

Profile tolerances can be applied _________ or __________.

_________________ tolerances are 2-dimensional controls.

____________________ tolerances are 3-dimensional controls.

Questions #1-9 Fill in blanks (choose from below)

6. _________________ can be used when different tolerances are

required for location and form and/or orientation.

7. When using profile tolerances to control the location and/or orientation of

a feature, a _______________ must be included

in the feature control frame.

8. When using profile tolerances to control form only, a ______

__________ is not required in the feature control frame.

9.

profile of a linedatum reference

composite profile bilateral

location form

primary datum

true geometric counterpart

orientationprofile of a surface

unilateral

virtual condition

Page 48: 21917046 Machining Symbols

Tolerances of Location

True Position

Concentricity

Symmetry

(ASME Y14.5M-1994, 5.2)

(ASME Y14.5M-1994, 5.12)

(ASME Y14.5M-1994, 5.13)

Page 49: 21917046 Machining Symbols

Notes

Page 50: 21917046 Machining Symbols

10.25 +/- 0.5

10.25 +/- 0.5

8.5 +/- 0.1

RectangularTolerance Zone

10.25

10.25

8.5 +/- 0.1

Circular Tolerance

Zone

B

A

C

Coordinate vs Geometric

Tolerancing Methods

Coordinate Dimensioning Geometric Dimensioning

Rectangular Tolerance Zone Circular Tolerance Zone

1.4

+/- 0.5

+/- 0.5

57% LargerTolerance Zone

Circular Tolerance Zone

Rectangular Tolerance Zone

Increased Effective Tolerance

1.4 A B C

Page 51: 21917046 Machining Symbols

Formula to determine the actual radial position of a feature using measured coordinate values (RFS)

Z positional tolerance /2

X2 Y2+Z =

X =2

Y =2

X

Y

ZFeature axis actual

location (measured)

Positional

tolerance zone

cylinder

Feature axis true

position (designed)

Positional Tolerance Verification

Z = total radial deviation

“X” measured deviation

“Y” measured deviation

Actual feature

boundary

(Applies when a circular tolerance is indicated)

Page 52: 21917046 Machining Symbols

Formula to determine the actual radial position of a feature using measured coordinate values (MMC)

Z

X2 Y2+Z =

X =2

Y =2

X

Y

ZFeature axis actual

location (measured)

Positional

tolerance zone

cylinder

Feature axis true

position (designed)

Positional Tolerance Verification

Z = total radial deviation

“X” measured deviation

“Y” measured deviation

Actual feature

boundary

+( actual - MMC)

2

= positional tolerance

(Applies when a circular tolerance is indicated)

Page 53: 21917046 Machining Symbols

Bi-directional True PositionRectangular Coordinate Method

3510

10

AC

B

1.5 A B C

0.5 A B C2X

2X

10 35

1.5 WideTolerance

Zone

0.5 WideTolerance Zone

True Position Relatedto Datum Reference Frame

10B

C

Each axis must lie within the 1.5 X 0.5 rectangular tolerance zone

basically located to the datum reference frame

As Shownon Drawing

Means This:

2X 6 +/-0.25

Page 54: 21917046 Machining Symbols

Bi-directional True PositionMultiple Single-Segment Method

3510

10

AC

B

10 35

1.5 WideTolerance

Zone

0.5 WideTolerance Zone

True Position Relatedto Datum Reference Frame

10B

C

Each axis must lie within the 1.5 X 0.5 rectangular tolerance zone

basically located to the datum reference frame

As Shownon Drawing

Means This:

2X 6 +/-0.251.5 A B C

0.5 A B

Page 55: 21917046 Machining Symbols

3510

10

AC

B As Shownon Drawing

Means This:

1.5 A B C 0.5 A B CBOUNDARY BOUNDARY

10 3510

B

C

2X 13 +/-0.25 2X 6 +/-0.25

12.75 MMC width of slot

-1.50 Position tolerance

11.25 Maximum boundary

Both holes must be within the size limits and no

portion of their surfaces may lie within the area

described by the 11.25 x 5.25 maximum

boundaries when the part is positioned with respect to the datum reference frame. The

boundary concept can only be applied on an

MMC basis.

o90

True position boundary related

to datum reference frame

A

Bi-directional True PositionNoncylndrical Features (Boundary Concept)

MM

5.75 MMC length of slot

-0.50 Position tolerance

5.25 maximum boundary

Page 56: 21917046 Machining Symbols

Composite True PositionWithout Pattern Orientation Control

3510

10

AC

B

10 35

True Position Relatedto Datum ReferenceFrame

10B

C

Each axis must lie within each tolerance zone simultaneously

As Shownon Drawing

Means This:

2X 6 +/-0.251.5 A B C

0.5 A

0.5 Feature-RelatingTolerance Zone Cylinder

1.5 Pattern-LocatingTolerance Zone Cylinder

pattern location relative to Datums A, B, and Cpattern orientation relative to

Datum A only (perpendicularity)

Page 57: 21917046 Machining Symbols

Composite True PositionWith Pattern Orientation Control

3510

10

AC

B

10 35

True Position Relatedto Datum ReferenceFrame

10B

C

Each axis must lie within each tolerance zone simultaneously

As Shownon Drawing

Means This:

2X 6 +/-0.25

0.5 Feature-RelatingTolerance Zone Cylinder

1.5 Pattern-LocatingTolerance Zone Cylinder

pattern location relative to Datums A, B, and C

pattern orientation relative to Datums A and B

1.5 A B C

0.5 A B

Page 58: 21917046 Machining Symbols

Location (Concentricity)Datum Features at RFS

A

15.95

15.90

As Shown on Drawing

Derived Median Points of

Diametrically Opposed Elements

Axis of Datum

Feature AMeans This:

Within the limits of size and regardless of feature size, all median points of

diametrically opposed elements must lie within a 0.5 cylindrical

tolerance zone. The axis of the tolerance zone coincides with the axis of

datum feature A. Concentricity can only be applied on an RFS basis.

0.5 A

6.35 +/- 0.05

0.5 Coaxial

Tolerance Zone

Page 59: 21917046 Machining Symbols

Location (Symmetry)Datum Features at RFS

A

15.95

15.90

0.5 A

6.35 +/- 0.05

Derived Median

Points

Center Plane of

Datum Feature A

0.5 Wide

Tolerance ZoneMeans This:

Within the limits of size and regardless of feature size, all median points

of opposed elements must lie between two parallel planes equally

disposed about datum plane A, 0.5 apart. Symmetry can only be

applied on an RFS basis.

As Shown on Drawing

Page 60: 21917046 Machining Symbols

True Position Quiz

Answer questions #1-11 True or False

Positional tolerances are applied to individual or patternsof features of size.

1.

Cylindrical tolerance zones more closely represent thefunctional requirements of a pattern of clearance holes.

True position tolerances can control a feature’s size.

Positional tolerances are applied on an MMC, LMC, orRFS basis.

2.

3.

4.

5.

True position tolerance values are used to calculate the minimum size of a feature required for assembly.

6. Composite true position tolerances should be avoidedbecause it is overly restrictive and difficult to check.

Composite true position tolerances can only be appliedto patterns of related features.

7.

The tolerance value shown in the upper segment of acomposite true position feature control frame appliesto the location of a pattern of features to the specifieddatums.

8.

Positional tolerances can be used to control circularity

9.

10.

11.

The tolerance value shown in the lower segment of acomposite true position feature control frame appliesto the location of a pattern of features to the specifieddatums.

True position tolerances can be used to control centerdistance relationships between features of size.

Page 61: 21917046 Machining Symbols

Positional tolerance zones can be ___________, ___________,

or spherical

1.

2.

3.

4.

5.

________________ are used to establish the true (theoretically

exact) position of a feature from specified datums.

Positional tolerancing is a _____________ control.

Positional tolerance can apply to the ____ or ________________ of

a feature.

_____ and ________ fastener equations are used to determine

appropriate clearance hole sizes for mating details

6.

7.

_________ tolerance zones are recommended to prevent fastener

interference in mating details.

8.

projected3-dimensional

surface boundary floating

location fixed

basic dimensions

maximum material

cylindricalpattern-locating rectangular

feature-relating

True Position Quiz

Questions #1-9 Fill in blanks (choose from below)

The tolerance shown in the upper segment of a composite true

position feature control frame is called the ________________tolerance zone.

The tolerance shown in the lower segment of a composite true

position feature control frame is called the ________________tolerance zone.

9. Functional gaging principles can be applied when __________

________ condition is specified

axis

Page 62: 21917046 Machining Symbols

Notes

Page 63: 21917046 Machining Symbols

Notes

Page 64: 21917046 Machining Symbols

Fixed and

Floating

Fastener

Exercises

Page 65: 21917046 Machining Symbols

2x M10 X 1.5(Reference)

B

A

?.?

2x 10.50 +/- 0.25

M Calculate Required

Positional Tolerance

0.5

2x ??.?? +/- 0.25

M

Calculate

Nominal Size

A

B

T = H - FH = Minimum Hole Size = 10.25 F = Max. Fastener Size = 10

T = 10.25 -10

T = ______

Floating Fasteners

H = F +TF = Max. Fastener Size = 10T = Positional Tolerance = 0.50

H = 10 + 0.50

H = ______

In applications where two or more mating details are assembled, and all parts have clearance holes for the fasteners, the floating fastener formula shown below can be used to calculate the appropriate hole sizes or positional tolerance requirements to ensure assembly. The formula will provide a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance

H= Min. diameter of clearance hole F= Maximum diameter of fastener T= Positional tolerance diameter

H=F+T or T=H-F

General Equation Applies to Each Part Individually

remember: the size tolerance must be

added to the calculated MMC hole size to

obtain the correct nominal value.

Page 66: 21917046 Machining Symbols

2x M10 X 1.5(Reference)

B

A

0.25

2x 10.50 +/- 0.25

M

0.5

2x 10.75 +/- 0.25

M

A

B

Floating Fasteners

REMEMBER!!! All Calculations Apply at MMC

H= Min. diameter of clearance hole F= Maximum diameter of fastener T= Positional tolerance diameter

H=F+T or T=H-F

General Equation Applies to Each Part Individually

T = H - FH = Minimum Hole Size = 10.25 F = Max. Fastener Size = 10

T = 10.25 -10

T = 0.25

Calculate Required

Positional Tolerance

F = Max. Fastener Size = 10T = Positional Tolerance = 0.5

H = 10 + .5

H = 10.5 Minimum

H = F +T

In applications where two or more mating details are assembled, and all parts have clearance holes for the fasteners, the floating fastener formula shown below can be used to calculate the appropriate hole sizes or positional tolerance requirements to ensure assembly. The formula will provide a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance

remember: the size tolerance must be

added to the calculated MMC hole size to

obtain the correct nominal value.Calculate

Nominal Size

Page 67: 21917046 Machining Symbols

F = Max. Fastener Size = 10.00 T = Positional Tolerance = 0.80

2x M10 X 1.5(Reference)

B

A

0.8

2x ??.?? +/- 0.25

M

Calculate Required

Clearance Hole Size.

2X M10 X 1.5

A

B

Fixed Fasteners

H = 10.00 + 2(0.8)

H = _____

H= Min. diameter of clearance hole F= Maximum diameter of fastener T= Positional tolerance diameter

H=F+2T or T=(H-F)/2

General Equation Used When Positional Tolerances Are Equal

In fixed fastener applications where two mating details have equal positional tolerances, the fixed fastener formula shown below can be used to calculate the appropriate minimum clearance hole size and/or positional tolerance required to ensure assembly. The formula provides a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance. (Note that in this example the positional tolerances indicated are the same for both parts.)

0.8 M 10P

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED

Nominal Size

(MMC For Calculations)

H = F + 2T

remember: the size tolerance

must be added to the calculated

MMC size to obtain the correct

nominal value.

10

Page 68: 21917046 Machining Symbols

2x M10 X 1.5(Reference)

B

A

2x 11.85 +/- 0.25

0.8 M

Calculate Required

Clearance Hole Size.

A

B

In fixed fastener applications where two mating details have equal positional tolerances, the fixed fastener formula shown below can be used to calculate the appropriate minimum clearance hole size and/or positional tolerance required to ensure assembly. The formula provides a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance. (Note that in this example the positional tolerances indicated are the same for both parts.)

Fixed Fasteners

H = F + 2TF = Max. Fastener Size = 10.00 T = Positional Tolerance = 0.80

H = 10.00 + 2(0.8)

H = 11.60 Minimum

H= Min. diameter of clearance hole F= Maximum diameter of fastener T= Positional tolerance diameter

H=F+2T or T=(H-F)/2

General Equation Used When Positional Tolerances Are Equal

0.8 M 10P

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED

2X M10 X 1.5Nominal Size

(MMC For Calculations)

remember: the size tolerance

must be added to the calculated

MMC size to obtain the correct

nominal value.

REMEMBER!!! All Calculations Apply at MMC

10

Page 69: 21917046 Machining Symbols

2x M10 X 1.5(Reference)

B

A

2x 11.85 +/- 0.25

0.8 M

Calculate Required

Clearance Hole Size.

A

B

In fixed fastener applications where two mating details have equal positional tolerances, the fixed fastener formula shown below can be used to calculate the appropriate minimum clearance hole size and/or positional tolerance required to ensure assembly. The formula provides a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance. (Note that in this example the positional tolerances indicated are the same for both parts.)

Fixed Fasteners

H = F + 2TF = Max. Fastener Size = 10T = Positional Tolerance = 0.8

H = 10 + 2(0.8)

H = 11.6 Minimum

H= Min. diameter of clearance hole F= Maximum diameter of fastener T= Positional tolerance diameter

H=F+2T or T=(H-F)/2

General Equation Used When Positional Tolerances Are Equal

0.8 M 10P

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED

2X M10 X 1.5Nominal Size

(MMC For Calculations)

remember: the size tolerance

must be added to the calculated

MMC size to obtain the correct

nominal value.

REMEMBER!!! All Calculations Apply at MMC

10

Page 70: 21917046 Machining Symbols

2x M10 X 1.5(Reference)

B

A

0.5

2x 11.25 +/- 0.25

MCalculate Required

Positional Tolerance .

(Both Parts)

A

B

In applications where two mating details are assembled, and one part has restrained fasteners, the fixed fastener formula shown below can be used to calculate appropriate hole sizes and/or positional tolerances required to ensure assembly. The formula will provide a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance. (Note: in this example the resultant positional tolerance is applied to both parts equally.)

Fixed Fasteners

T = (H - F)/2H = Minimum Hole Size = 11F = Max. Fastener Size = 10

T = (11 - 10)/2

T = 0.50

H= Min. diameter of clearance hole F= Maximum diameter of fastener T= Positional tolerance diameter

H=F+2T or T=(H-F)/2

General Equation Used When Positional Tolerances Are Equal

2X M10 X 1.5

0.5 M 10P

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED

Nominal Size

(MMC For Calculations)

REMEMBER!!! All Calculations Apply at MMC

10

Page 71: 21917046 Machining Symbols

2x M10 X 1.5(Reference)

B

A

0.5

2x ??.?? +/- 0.25

M

Calculate Required

Clearance Hole Size.

A

B

Fixed Fasteners

H = Min. diameter of clearance hole F = Maximum diameter of fastener T1= Positional tolerance (Part A) T2= Positional tolerance (Part B)

H=F+(T1 + T2)

General Equation Used When Positional Tolerances Are Not Equal

F = Max. Fastener Size = 10T1 = Positional Tol. (A) = 0.50 T2 = Positional Tol. (B) = 1

H = 10+ (0.5 + 1)

H = ____

H=F+(T1 + T2)

In fixed fastener applications where two mating details have unequal positional tolerances, the fixed fastener formula shown below can be used to calculate the appropriate minimum clearance hole size and/or positional tolerances required to ensure assembly. The formula provides a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance. (Note that in this example the positional tolerances indicated are not equal.)

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED

2X M10 X 1.5Nominal Size

(MMC For Calculations)

remember: the size tolerance must be

added to the calculated MMC hole size to

obtain the correct nominal value.

10

1 M 10P

Page 72: 21917046 Machining Symbols

2x M10 X 1.5(Reference)

B

A

0.5

2x 11.75 +/- 0.25

M

Calculate Required

Clearance Hole Size.

A

B

In fixed fastener applications where two mating details have unequal positional tolerances, the fixed fastener formula shown below can be used to calculate the appropriate minimum clearance hole size and/or positional tolerances required to ensure assembly. The formula provides a “zero-interference” fit when the features are at MMC and at their extreme of positional tolerance. (Note that in this example the positional tolerances indicated are not equal.)

Fixed Fasteners

F = Max. Fastener Size = 10T1 = Positional Tol. (A) = 0.5 T2 = Positional Tol. (B) = 1

H = 10 + (0.5 + 1)

H = 11.5 Minimum

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED

H = Min. diameter of clearance hole F = Maximum diameter of fastener T1= Positional tolerance (Part A) T2= Positional tolerance (Part B)

H= F+(T1 + T2)

General Equation Used When Positional Tolerances Are Not Equal

H=F+(T1 + T2)

1 M 10P

2X M10 X 1.5Nominal Size

(MMC For Calculations)

remember: the size tolerance must be

added to the calculated MMC hole size to

obtain the correct nominal value.

REMEMBER!!! All Calculations Apply at MMC

10

Page 73: 21917046 Machining Symbols

D

P

H F

A

B

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS NOT USED

2x 10.05 +/-0.05

B

A

0.5 M

2x ??.?? +/-0.25Calculate

Nominal Size

0.5 M

In applications where a projected tolerance zone is not indicated, it is necessary to select a positional tolerance and minimum clearance hole size combination that will allow for any out-of-squareness of the feature containing the fastener. The modified fixed fastener formula shown below can be used to calculate the appropriate minimum clearance hole size required to ensure assembly. The formula provides a “zero-interference” fit when the features are at MMC and at the extreme positional tolerance.

Fixed Fasteners

H = 10.00 + 0.5 + 0.5(1 + 2(15/20))

H = __________

H= F + T1 + T2 (1+(2P/D))

remember: the size tolerance must be

added to the calculated MMC hole size to

obtain the correct nominal value.

H= Min. diameter of clearance hole F= Maximum diameter of pin T1= Positional tolerance (Part A) T2= Positional tolerance (Part B) D= Min. depth of pin (Part A) P= Maximum projection of pin

F = Max. pin size = 10T1 = Positional Tol. (A) = 0.5T2 = Positional Tol. (B) = 0.5 D = Min. pin depth = 20. P = Max. pin projection = 15

Page 74: 21917046 Machining Symbols

D

P

H F

A

B

H= Min. diameter of clearance hole F= Maximum diameter of pin T1= Positional tolerance (Part A) T2= Positional tolerance (Part B) D= Min. depth of pin (Part A) P= Maximum projection of pin

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS NOT USED

2x 10.05 +/-0.05

B

A

0.5 M

2x 12 +/-0.25Calculate

Nominal Size

0.5 M

F = Max. pin size = 10T1 = Positional tol. (A) = 0.5T2 = Positional tol. (B) = 0.5 D = Min. pin depth = 20 P = Max. pin projection = 15

H= F + T1 + T2 (1+(2P/D))

H = 10 + 0.5 + 0.5(1 + 2(15/20))

H = 11.75 Minimum

In applications where a projected tolerance zone is not indicated, it is necessary to select a positional tolerance and minimum clearance hole size combination that will allow for any out-of-squareness of the feature containing the fastener. The modified fixed fastener formula shown below can be used to calculate the appropriate minimum clearance hole size required to ensure assembly. The formula provides a “zero-interference” fit when the features are at MMC and at the extreme positional tolerance.

Fixed Fasteners

H= F + T1 + T2 (1+(2P/D))

REMEMBER!!! All Calculations Apply at MMC

remember: the size tolerance must be

added to the calculated MMC hole size to

obtain the correct nominal value.

Page 75: 21917046 Machining Symbols

Answers to Quizzes

and Exercises

Page 76: 21917046 Machining Symbols

Rules and Definitions Quiz

1. Tight tolerances ensure high quality and performance.

2. The use of GD&T improves productivity.

3. Size tolerances control both orientation and position.

4. Unless otherwise specified size tolerances control form.

5. A material modifier symbol is not required for RFS.

6. A material modifier symbol is not required for MMC.

7. Title block default tolerances apply to basic dimensions.

8. A surface on a part is considered a feature.

9. Bilateral tolerances allow variation in two directions.

10. A free state modifier can only be applied to a tolerance.

11. A free state datum modifier applies to “assists” & “rests”.

12. Virtual condition applies regardless of feature size.

FALSE

TRUE

FALSE

TRUE

TRUE

FALSE

FALSE

TRUE

TRUE

TRUE

FALSE

FALSE

Questions #1-12 True or False

Page 77: 21917046 Machining Symbols

Material Condition Quiz

Internal Features MMC LMC

External Features MMC LMC

.890

.885

.895

.890

23.45 +0.05/-0.25

10.75 +0.25/-0

123. 5 +/-0.1

23.45 +0.05/-0.25

10.75 +0/-0.25

123. 5 +/-0.1

Calculate appropriate values

Fill in blanks

10.75 11

23.2 23.5

123.4 123.6

.890 .895

10.75 10.5

23.5 23.2

123.6 123.4

.890 .885

Page 78: 21917046 Machining Symbols

1. Datum target areas are theoretically exact.

2. Datum features are imaginary.

3. Primary datums have only three points of contact.

4. The 6 Degrees of Freedom are U/D, F/A, & C/C.

5. Datum simulators are part of the gage or tool.

6. Datum simulators are used to represent datums.

8. All datum features must be dimensionally stable.

9. Datum planes constrain degrees of freedom.

10. Tertiary datums are not always required.

12. Datums should represent functional features.

Datum Quiz

11. All tooling locators (CD’s) are used as datums.

Questions #1-12 True or False

7. Datums are actual part features.

FALSE

FALSE

FALSE

FALSE

TRUE

TRUE

FALSE

TRUE

TRUE

TRUE

FALSE

TRUE

Page 79: 21917046 Machining Symbols

Datum Quiz

The three planes that make up a basic datum reference

frame are called primary, secondary, and tertiary.

An unrestrained part will exhibit 3-linear and 3-rotational degrees

of freedom.

A planar primary datum plane will restrain 1-linear and 2-rotationaldegrees of freedom.

The primary and secondary datum planes together will restrain five degrees

of freedom.

The primary, secondary and tertiary datum planes together will

restrain all six degrees of freedom.

The purpose of a datum reference frame is to restrain movementof a part in a gage or tool.

A datum must be functional, repeatable, and coordinated.

A datum feature is an actual feature on a part.

A datum is a theoretically exact point, axis or plane.

A datum simulator is a precise surface used to establish a

simulated datum.

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Questions #1-10 Fill in blanks (choose from below)

primary

secondary

tertiary 3-rotational

3-linear

2-rotational

datum

three

two

one

six

functional

restrain movement coordinated

datum simulator

datum feature

repeatablefive

1-linear

Page 80: 21917046 Machining Symbols

Straightness and circularity are individual line or circular

element (2-D) controls.

Form Control Quiz

The four form controls are straightness, flatness,

circularity, and cylindricity.

Rule #1 states that unless otherwise specified a feature of

size must have perfect form at MMC.

Flatness and cylindricity are surface (3-D) controls.

Circularity can be applied to both straight and tapered cylindrical

parts.

1.

2.

3.

4.

5.

Form controls require a datum reference.

Form controls do not directly control a feature’s size.

A feature’s form tolerance must be less than it’s sizetolerance.

Flatness controls the orientation of a feature.

Size limits implicitly control a feature’s form.

6.

7.

8.

9.

10.

FALSE

TRUE

TRUE

TRUE

FALSE

Answer questions #6-10 True or False

Questions #1-5 Fill in blanks (choose from below)

straightness

flatness

circularity

cylindricity

perfect form

straight tapered profile

true position

angularity

Page 81: 21917046 Machining Symbols

Orientation Control Quiz

The three orientation controls are angularity, parallelism,

and perpendicularity.

1.

2.

3.

4.

5.

A datum reference is always required when applying any of

the orientation controls.

Perpendicularity is the appropriate geometric tolerance when

controlling the orientation of a feature at right angles to a datumreference.

Orientation tolerances indirectly control a feature’s form.

Mathematically all three orientation tolerances are identical.

Orientation tolerances do not control the location of a feature.

Answer questions #6-10 True or False

6. TRUE

Orientation tolerance zones can be cylindrical.

Parallelism tolerances do not apply to features of size.

To apply an angularity tolerance the desired angle mustbe indicated as a basic dimension.

7.

8.

9.

10.

TRUE

FALSE

FALSE

TRUE

To apply a perpendicularity tolerance the desired anglemust be indicated as a basic dimension.

Questions #1-5 Fill in blanks (choose from below)

angularity

perpendicularity

parallelism

datum reference

identical

location

profile

datum feature

datum target

Page 82: 21917046 Machining Symbols

Runout Control Quiz

Answer questions #1-12 True or False

TRUE

Total runout is a 2-dimensional control.1.

Runout tolerances are used on rotating parts.

Total runout tolerances should be applied at MMC.

Runout tolerances can be applied to surfaces at rightangles to the datum reference.

2.

3.

4.

5.

FALSE

Circular runout tolerances apply to single elements .

FALSE

TRUE

TRUE

6. Circular runout tolerances are used to control an entirefeature surface.

Runout tolerances always require a datum reference.7.

Circular runout and total runout both control axis to surface relationships.

8. TRUE

Circular runout can be applied to control taper of a part.9. FALSE

Total runout tolerances are an appropriate way to limit “wobble” of a rotating surface.

10.

Runout tolerances are used to control a feature’s size.11.

Total runout can control circularity, straightness, taper,coaxiality, angularity and any other surface variation.

12. TRUE

FALSE

TRUE

TRUE

FALSE

Page 83: 21917046 Machining Symbols

In composite profile applications, the tolerance shown in the upper

segment of the feature control frame applies only to the location of the

feature.

Profile Control Quiz

The two types of profile tolerances are profile of a line, and

profile of a surface.1.

2.

3.

4.

5.

Profile tolerances can be used to control the location, form,

orientation, and sometimes size of a feature.

Profile tolerances can be applied bilateral or unilateral.

Profile of a line tolerances are 2-dimensional controls.

Profile of a surface tolerances are 3-dimensional controls.

Questions #1-9 Fill in blanks (choose from below)

6. Composite Profile can be used when different tolerances are

required for location and form and/or orientation.

7. When using profile tolerances to control the location and/or orientation of

a feature, a datum reference must be included in the feature control

frame.

8. When using profile tolerances to control form only, a datum

reference is not required in the feature control frame.

9.

profile of a linedatum reference

composite profile bilateral

location form

primary datum

true geometric counterpart

orientationprofile of a surface

unilateral

virtual condition

Page 84: 21917046 Machining Symbols

6.

Profile Control QuizProfile Control QuizProfile Control QuizProfile Control Quiz

Profile tolerances always require a datum reference.

Answer questions #1-13 True or False

1.

Profile of a surface tolerance is a 2-dimensional control.

Profile of a line tolerances should be applied at MMC.

Profile tolerances can be applied to features of size.

2.

3.

4.

5.

Profile of a surface tolerance should be used to control

trim edges on sheet metal parts.

Profile tolerances can be combined with other geometric

controls such as flatness to control a feature.

Profile of a line tolerances apply to an entire surface.7.

Profile of a line controls apply to individual line elements.8.

Profile tolerances only control the location of a surface.9.

Composite profile controls should be avoided because

they are more restrictive and very difficult to check.10.

Profile tolerances can be applied either bilateral or

unilateral to a feature.11.

Profile tolerances can be applied in both freestate and

restrained datum conditions.12.

Tolerances shown in the lower segment of a composite

profile feature control frame control the location of a

feature to the specified datums.

13.

TRUETRUETRUETRUE

FALSEFALSEFALSEFALSE

FALSEFALSEFALSEFALSE

FALSEFALSEFALSEFALSE

TRUETRUETRUETRUE

TRUETRUETRUETRUE

TRUETRUETRUETRUE

FALSEFALSEFALSEFALSE

FALSEFALSEFALSEFALSE

FALSEFALSEFALSEFALSE

TRUETRUETRUETRUE

TRUETRUETRUETRUE

FALSEFALSEFALSEFALSE

Page 85: 21917046 Machining Symbols

True Position QuizTrue Position QuizTrue Position QuizTrue Position Quiz

Answer questions #1-11 True or False

TRUETRUETRUETRUE

Positional tolerances are applied to individual or patterns

of features of size.1.

Cylindrical tolerance zones more closely represent the

functional requirements of a pattern of clearance holes.

True position tolerances can control a feature’s size.

Positional tolerances are applied on an MMC, LMC, or

RFS basis.

2.

3.

4.

5.

FALSEFALSEFALSEFALSE

True position tolerance values are used to calculate the

minimum size of a feature required for assembly.

TRUETRUETRUETRUE

TRUETRUETRUETRUE

6. Composite true position tolerances should be avoidedbecause it is overly restrictive and difficult to check.

Composite true position tolerances can only be applied

to patterns of related features.7.

The tolerance value shown in the upper segment of a

composite true position feature control frame applies

to the location of a pattern of features to the specified

datums.

8. TRUETRUETRUETRUE

Positional tolerances can be used to control circularity

9. FALSEFALSEFALSEFALSE

10.

11. TRUETRUETRUETRUE

FALSEFALSEFALSEFALSE

TRUETRUETRUETRUE

FALSEFALSEFALSEFALSE

TRUETRUETRUETRUE

The tolerance value shown in the lower segment of a

composite true position feature control frame applies

to the location of a pattern of features to the specified

datums.

True position tolerances can be used to control center

distance relationships between features of size.

Page 86: 21917046 Machining Symbols

Positional tolerance zones can be rectangular, cylindrical,or spherical

1.

2.

3.

4.

5.

Basic dimensions are used to establish the true (theoretically

exact) position of a feature from specified datums.

Positional tolerancing is a 3-dimensional control.

Positional tolerance can apply to the axis or surface boundaryof a feature.

Fixed and floating fastener equations are used to determine

appropriate clearance hole sizes for mating details

6.

7.

Projected tolerance zones are recommended to prevent fastener

interference in mating details.

8.

projected3-dimensional

surface boundary floating

location fixed

basic dimensions

maximum material

cylindricalpattern-locating rectangular

feature-relating

True Position Quiz

Questions #1-9 Fill in blanks (choose from below)

The tolerance shown in the upper segment of a composite true

position feature control frame is called the pattern-locatingtolerance zone.

The tolerance shown in the lower segment of a composite true

position feature control frame is called the feature-relatingtolerance zone.

9. Functional gaging principles can be applied when maximum

material condition is specified

axis

Page 87: 21917046 Machining Symbols

E

N

D

Page 88: 21917046 Machining Symbols

Notes

Page 89: 21917046 Machining Symbols

Notes

Page 90: 21917046 Machining Symbols

Notes

Page 91: 21917046 Machining Symbols

Extreme Variations of Form

Allowed By Size Tolerance25.1

25

25

24.9

25

(MMC)

25.1

(LMC)

25.1

(LMC)

25

(MMC)24.9

(LMC)

24.9

(LMC)

25

(MMC)

25.1

(LMC)

MMC Perfect

Form Boundary25

(MMC)

24.9

(LMC)

Page 92: 21917046 Machining Symbols

Virtual and

Resultant

Condition

Boundaries

Internal and External

Features (MMC Concept)

Page 93: 21917046 Machining Symbols

Virtual Condition BoundaryInternal Feature (MMC Concept)

12.5 Virtual Condition Boundary

13.5 MMC Size of Feature

1 Applicable Geometric Tolerance

Calculating Virtual Condition

1 A B CM

14 +/- 0.5

C

BXX.X

XX.X

A

As Shown on Drawing

Axis Location of

MMC Hole Shown at Extreme Limit

Boundary of MMC Hole

Shown at Extreme Limit

1 Positional

Tolerance Zone at

MMC

True (Basic)Position of Hole

True (Basic)

Position of Hole

Other Possible

Extreme Locations

Virtual Condition

Inner BoundaryMaximum Inscribed

Diameter( )

Page 94: 21917046 Machining Symbols

Resultant Condition BoundaryInternal Feature (MMC Concept)

1 A B CM

14 +/- 0.5

C

BXX.X

XX.X

A

16.5 Resultant Condition Boundary

14.5 LMC Size of Feature

2 Geometric Tolerance (at LMC)

Calculating Resultant Condition (Internal Feature)

As Shown on Drawing

Axis Location of

LMC Hole Shown at Extreme Limit

Boundary of LMC Hole

Shown at Extreme Limit

2 Positional

Tolerance Zone at

LMC

True (Basic)Position of Hole

True (Basic)

Position of Hole

Other Possible

Extreme Locations

Resultant Condition

Outer BoundaryMinimum Circumscribed

Diameter( )

Page 95: 21917046 Machining Symbols

Virtual Condition BoundaryExternal Feature (MMC Concept)

15.5 Virtual Condition Boundary

14.5 MMC Size of Feature

1 Applicable Geometric Tolerance

Calculating Virtual Condition

1 A B CM

14 +/- 0.5

C

BXX.X

XX.XX

A

As Shown on Drawing

Axis Location of

MMC Feature Shown at Extreme Limit

Boundary of MMC Feature

Shown at Extreme Limit

1 Positional

Tolerance Zone at

MMC

True (Basic)Position of Feature

True (Basic)

Position of Feature

Other Possible

Extreme Locations

Virtual Condition

Outer BoundaryMinimum Circumscribed

Diameter( )

Page 96: 21917046 Machining Symbols

Resultant Condition BoundaryExternal Feature (MMC Concept)

1 A B CM

14 +/- 0.5

C

BXX.X

XX.X

A

11.5 Resultant Condition Boundary

13.5 LMC Size of Feature

2 Geometric Tolerance (at LMC)

Calculating Resultant Condition (External Feature)

As Shown on Drawing

Axis Location of

LMC Feature Shown at Extreme Limit

Boundary of LMC feature

Shown at Extreme Limit

2 Positional

Tolerance Zone at

LMC

True (Basic)Position of Feature

True (Basic)

Position of Feature

Other Possible

Extreme Locations

Resultant Condition

Inner Boundary

Maximum Inscribed

Diameter( )