Download - 2-GD & T
-
8/7/2019 2-GD & T
1/96
Based on the ASME Y14.5MBased on the ASME Y14.5M--
1994 Dimensioning and1994 Dimensioning and
Tolerancing StandardTolerancing Standard
DIMENSIONALENGINEERING
-
8/7/2019 2-GD & T
2/96
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)
-
8/7/2019 2-GD & T
3/96
25 +/-0.25
0.1 Tolerance
0.5 Tolerance
Straightness is the condition where an element of asurface or an axis is a straight line
Straightness(Flat Surfaces)
0.5 0.1
-
8/7/2019 2-GD & T
4/96
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 linesseparated by the specified tolerance value applied to eachview. All points on the surface must lie within the limits ofsize and the applicable straightness limit.
-
8/7/2019 2-GD & T
5/96
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 mustlie within a tolerance zone defined by two parallel linesseparated by the specified tolerance value. The feature mustbe within the limits of size and the boundary of perfect form atMMC. Any barreling or waisting of the feature must notexceed the size limits of the feature.
-
8/7/2019 2-GD & T
6/96
Straightness (RFS)
0.1
Outer Boundary (Max)
MMC
0.1 DiameterTolerance Zone
Outer Boundary = Actual Feature Size + Straightness Tolerance
In this example the derived median line of the features actual local size
must lie within a tolerance zone defined by a cylinder whose diameter isequal to the specified tolerance value regardless of the feature size.Each circular element of the feature must be within the specified limits ofsize. However, the boundary of perfect form at MMC can be violated upto the maximum outer boundary or virtual condition diameter.
-
8/7/2019 2-GD & T
7/96
Straightness (MMC)1514.85
15.1 Virtual Condition
15(MMC)
0.1 DiameterTolerance Zone
15.1 Virtual Condition
14.85(LMC)
0.25 DiameterTolerance Zone
Virtual Condition = MMC Feature Size + Straightness Tolerance
In this example the derived median line of the features actual local size
must lie within a tolerance zone defined by a cylinder whose diameter isequal to the specified tolerance value at MMC. As each circular elementof the feature departs from MMC, the diameter of the tolerance cylinderis allowed to increase by an amount equal to the departure from the localMMC size. Each circular element of the feature must be within thespecified limits of size. However, the boundary of perfect form at MMC
can be violated up to the virtual condition diameter.
0.1 M
-
8/7/2019 2-GD & T
8/96
Flatness
Flatness is the condition of a surface having all elements inone plane. Flatness must fall within the limits of size. Theflatness 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 tolerancezone defined by two parallel planes separated by the specifiedtolerance value. All points on the surface must lie within the
limits of size and the flatness limit.
-
8/7/2019 2-GD & T
9/96
Circularity is the condition of a surface where all points of thesurface intersected by any plane perpendicular to a commonaxis 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 atolerance zone defined by two concentric circles separated by the
specified tolerance value. All points on the surface must lie within thelimits of size and the circularity limit.
0.1
-
8/7/2019 2-GD & T
10/96
Cylindricity
Cylindricity is the condition of a surface of revolution in whichall points are equidistant from a common axis. Cylindricity is acomposite 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 zonedefined by two concentric cylinders separated by the specifiedtolerance value. All points on the surface must lie within the limits of
size and the cylindricity limit.
-
8/7/2019 2-GD & T
11/96
____________ and___________ are individual line or circularelement (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_______ cylindricalparts.
1.
2.
3.
4.
5.
Form controls require a datum reference.
Form controls do not directly control a features size.
A features form tolerance must be less than its size
tolerance.
Flatness controls the orientation of a feature.
Size limits implicitly control a features 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
-
8/7/2019 2-GD & T
12/96
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)
-
8/7/2019 2-GD & T
13/96
Angularity(Feature Surface to Datum Surface)
Angularity is the condition of the planar feature surface at aspecified angle (other than 90 degrees) to the datumreference plane, within the specified tolerance zone.
A
20 +/-0.5
30 o
A
19.5 min
0.3 WideTolerance
Zone
30 o
A
20.5 max
0.3 WideTolerance
Zone
30 o
The tolerance zone in this example is defined
by two parallel planes oriented at thespecified angle to the datum reference plane.
0.3 A
-
8/7/2019 2-GD & T
14/96
Angularity is the condition of the feature axis at a specifiedangle (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, orientedat the specified angle to the datum reference plane.
0.3 CircularTolerance Zone
0.3 CircularTolerance Zone
Angularity(Feature Axis to Datum Surface)
NOTE: Tolerance appliesto feature at RFS
-
8/7/2019 2-GD & T
15/96
0.3 CircularTolerance Zone
NOTE: Tolerance
applies to feature
at RFS
Angularity is the condition of the feature axis at a specifiedangle (other than 90 degrees) to the datum reference axis,within the specified tolerance zone.
0.3 CircularTolerance Zone
A
Datum Axis A
Angularity(Feature Axis to Datum Axis)
The tolerance zone in this example is defined by acylinder equal to the length of the feature, oriented
at the specified angle to the datum reference axis.
NOTE: Feature axis must liewithin tolerance zone cylinder
0.3 A
o45
-
8/7/2019 2-GD & T
16/96
0.3 A
A
0.3 WideTolerance Zone
A A
Perpendicularity is the condition of the planar featuresurface at a right angle to the datum reference plane, within
the specified tolerance zone.
Perpendicularity(Feature Surface to Datum Surface)
0.3 WideTolerance Zone
The tolerance zone in this example is
defined by two parallel planes orientedperpendicular to the datum referenceplane.
-
8/7/2019 2-GD & T
17/96
C
Perpendicularity is the condition of the feature axis at a rightangle to the datum reference plane, within the specifiedtolerance zone.
Perpendicularity(Feature Axis to Datum Surface)
0.3 C
0.3 CircularTolerance Zone
0.3 DiameterTolerance Zone
0.3 CircularTolerance Zone
NOTE: Tolerance appliesto feature at RFS
The tolerance zone in this example is
defined by a cylinder equal to the length ofthe feature, oriented perpendicular to thedatum reference plane.
-
8/7/2019 2-GD & T
18/96
Perpendicularity(Feature Axis to Datum Axis)
NOTE: Tolerance appliesto feature at RFS
The tolerance zone in this example isdefined by two parallel planes oriented
perpendicular to the datum reference axis.
Perpendicularity is the condition of the feature axis at a rightangle to the datum reference axis, within the specifiedtolerance zone.
0.3 WideTolerance Zone
A
Datum Axis A
0.3 A
-
8/7/2019 2-GD & T
19/96
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 surfaceequidistant at all points from the datum reference plane,within the specified tolerance zone.
Parallelism(Feature Surface to Datum Surface)
The tolerance zone in this exampleis defined by two parallel planesoriented parallel to the datumreference plane.
-
8/7/2019 2-GD & T
20/96
A
0.3 WideTolerance Zone
Parallelism(Feature Axis to Datum Surface)
0.3 A
A
NOTE: The specified tolerance
does not apply to the orientationof the feature axis in this direction
Parallelism is the condition of the feature axis equidistantalong its length from the datum reference plane, within thespecified tolerance zone.
The tolerance zone in this exampleis defined by two parallel planes
oriented parallel to the datumreference plane.
NOTE: Tolerance appliesto feature at RFS
-
8/7/2019 2-GD & T
21/96
A
B
Parallelism(Feature Axis to Datum Surfaces)
A
B
0.3 CircularTolerance Zone
0.3 CircularTolerance Zone
0.3 CircularTolerance Zone
Parallelism is the condition of the feature axis equidistantalong its length from the two datum reference planes, withinthe specified tolerance zone.
The tolerance zone in this example is
defined by a cylinder equal to thelength of the feature, oriented parallelto the datum reference planes.
NOTE: Tolerance applies
to feature at RFS
0.3 A B
-
8/7/2019 2-GD & T
22/96
Parallelism(Feature Axis to Datum Axis)
Parallelism is the condition of the feature axis equidistant alongits length from the datum reference axis, within the specified
tolerance zone.
A
0.1 A
0.1 CircularTolerance Zone
0.1 Circular
Tolerance Zone
Datum Axis A
The tolerance zone in this example isdefined by a cylinder equal to thelength of the feature, oriented
parallel to the datum reference axis.
NOTE: Tolerance appliesto feature at RFS
-
8/7/2019 2-GD & T
23/96
Orientation Control Quiz
The three orientation controls are__________,___________,and________________.
1.
2.
3.
4.
5.
A_______________ is always required when applying any ofthe 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 features 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 must
be 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
-
8/7/2019 2-GD & T
24/96
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)
-
8/7/2019 2-GD & T
25/96
18 Max
Profile of a Line
2 Wide SizeTolerance Zone
1 A B C
A
17 +/- 1
1 Wide ProfileTolerance 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 twoparallel lines oriented with respect to the datum referenceframe. The profile tolerance zone is free to float within thelarger size tolerance and applies only to the form and
orientation of any individual line element along the entiresurface.
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 asa single entity is not required or desired. The tolerance applies to the lineelement of the surface at each individual cross section indicated on the
drawing.
16 Min.
-
8/7/2019 2-GD & T
26/96
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 featuresurface as a single entity is desired. The tolerance applies to the entiresurface and can be used to control size, location, form and/or orientation
of a feature surface.
Profile of a Surface
2 Wide Tolerance ZoneSize, Form and Orientation
A
A1
20 X 20
A2
20 X 20
A3
20 X 20
C 2 A B C
23.5
23.5 NominalLocation
The profile tolerance zone in this example is defined by two parallelplanes oriented with respect to the datum reference frame. The profiletolerance zone is located and aligned in a way that enables the partsurface to vary equally about the true profile of the feature.
B
-
8/7/2019 2-GD & T
27/96
Profile of a Surface
A1
20 X 20
A2
20 X 20
A3
20 X 20
B
C
50
B
C
50
1 Wide TotalTolerance 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 tolerancezone is located and aligned in a way that enables the part surface tovary 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 controlthe location, form and orientation of the entire trimmed surface. When abilateral value is specified, the tolerance zone allows the trim edge variationand/or locational error to be on both sides of the true profile. The tolerance
applies to the entire edge surface.
-
8/7/2019 2-GD & T
28/96
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 TotalTolerance Zone
(Unilateral Tolerance)
Profile of a Surface when applied to trim edges of sheet metal parts will controlthe location, form and orientation of the entire trimmed surface. When aunilateral value is specified, the tolerance zone limits the trim edge variationand/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 tolerancezone is located and aligned in a way that allows the trim surface to varyfrom the true profile only in the inboard direction.
0.5 A B C
Nominal Location
-
8/7/2019 2-GD & T
29/96
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 TotalTolerance Zone
(Unequal Bilateral Tolerance)
Profile of a Surface when applied to trim edges of sheet metal parts will controlthe location, form and orientation of the entire trimmed surface. Typically whenunequal values are specified, the tolerance zone will represent the actualmeasured 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 tolerancezone is located and aligned in a way that enables the part surface tovary from the true profile more in one direction (outboard) than in theother (inboard).
0.5
Nominal Location
-
8/7/2019 2-GD & T
30/96
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
-
8/7/2019 2-GD & T
31/96
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
-
8/7/2019 2-GD & T
32/96
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 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 afeature to the specified datums.
13.
-
8/7/2019 2-GD & T
33/96
In composite profile applications, the tolerance shown in the upper
segment of the feature control frame applies only to the________ ofthe 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 arerequired 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 includedin 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
-
8/7/2019 2-GD & T
34/96
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)
-
8/7/2019 2-GD & T
35/96
Notes
-
8/7/2019 2-GD & T
36/96
10.25 +/- 0.5
10.25 +/- 0.5
8.5 +/- 0.1
RectangularTolerance Zone
10.25
10.25
8.5 +/- 0.1
Circular ToleranceZone
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% Larger
Tolerance Zone
Circular Tolerance Zone
Rectangular Tolerance Zone
Increased Effective Tolerance
1.4 A B C
-
8/7/2019 2-GD & T
37/96
Formula to determine the actual radialposition of a feature using measuredcoordinate values (RFS)
Z positional tolerance /2
X2 Y2+Z =
X =2
Y =
2
X
Y
Z
Feature axis actuallocation (measured)
Positional
tolerance zonecylinder
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)
-
8/7/2019 2-GD & T
38/96
Formula to determine the actual radialposition of a feature using measuredcoordinate values (MMC)
Z
X2 Y2+Z =
X =2
Y =2
X
Y
Z
Feature axis actuallocation (measured)
Positional
tolerance zonecylinder
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)
-
8/7/2019 2-GD & T
39/96
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 Wide
Tolerance
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 Shown
on Drawing
Means This:
2X 6 +/-0.25
-
8/7/2019 2-GD & T
40/96
Bi-directional True PositionMultiple Single-Segment Method
3510
10
AC
B
10 35
1.5 Wide
Tolerance
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 Shown
on Drawing
Means This:
2X 6 +/-0.25
1.5 A B C0.5 A B
-
8/7/2019 2-GD & T
41/96
3510
10
AC
B As Shown
on 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 noportion of their surfaces may lie within the areadescribed by the 11.25 x 5.25 maximumboundaries when the part is positioned withrespect to the datum reference frame. Theboundary concept can only be applied on anMMC 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
-
8/7/2019 2-GD & T
42/96
Composite True PositionWithout Pattern Orientation Control
3510
10
AC
B
10 35
True Position Related
to Datum ReferenceFrame
10B
C
Each axis must lie within each tolerance zone simultaneously
As Shown
on Drawing
Means This:
2X 6 +/-0.25
1.5 A B C0.5 A
0.5 Feature-RelatingTolerance Zone Cylinder
1.5 Pattern-LocatingTolerance Zone Cylinder
patternlocationrelative
to Datums A, B, and Cpatternorientationrelative to
Datum A only (perpendicularity)
-
8/7/2019 2-GD & T
43/96
Composite True PositionWith Pattern Orientation Control
3510
10
AC
B
10 35
True Position Related
to Datum Reference
Frame
10B
C
Each axis must lie within each tolerance zone simultaneously
As Shown
on Drawing
Means This:
2X 6 +/-0.25
0.5 Feature-Relating
Tolerance Zone Cylinder
1.5 Pattern-LocatingTolerance Zone Cylinder
patternlocationrelative
to Datums A, B, and C
patternorientationrelative to
Datums A and B
1.5 A B C0.5 A B
-
8/7/2019 2-GD & T
44/96
Location (Concentricity)Datum Features at RFS
A
15.95
15.90
As Shown on Drawing
Derived Median Points ofDiametrically Opposed Elements
Axis of DatumFeature AMeans This:
Within the limits of size and regardless of feature size, all median points ofdiametrically opposed elements must lie within a 0.5 cylindricaltolerance zone. The axis of the tolerance zone coincides with the axis ofdatum feature A. Concentricity can only be applied on an RFS basis.
0.5 A
6.35 +/- 0.05
0.5 CoaxialTolerance Zone
-
8/7/2019 2-GD & T
45/96
Location (Symmetry)Datum Features at RFS
A
15.95
15.90
0.5 A
6.35 +/- 0.05
Derived MedianPoints
Center Plane ofDatum Feature A
0.5 WideTolerance ZoneMeans This:
Within the limits of size and regardless of feature size, all median pointsof opposed elements must lie between two parallel planes equallydisposed about datum plane A, 0.5 apart. Symmetry can only beapplied on an RFS basis.
As Shown on Drawing
-
8/7/2019 2-GD & T
46/96
True Position Quiz
Answer questions #1-11 True or False
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 features 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 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 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 applies
to the location of a pattern of features to the specifieddatums.
True position tolerances can be used to control center
distance relationships between features of size.
-
8/7/2019 2-GD & T
47/96
Positional tolerance zones can be___________,___________,or spherical
1.
2.
3.
4.
5.
________________ are used to establish the true (theoreticallyexact) position of a feature from specified datums.
Positional tolerancing is a_____________ control.
Positional tolerance can apply to the____ or________________ ofa feature.
_____ and________ fastener equations are used to determineappropriate clearance hole sizes for mating details
6.
7.
_________ tolerance zones are recommended to prevent fastenerinterference 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 trueposition 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
-
8/7/2019 2-GD & T
48/96
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)
-
8/7/2019 2-GD & T
49/96
Datum feature
Datum axis (establishedfrom datum feature
Angled surfacesconstructed arounda datum axis
External surfacesconstructed around
a datum axis
Internal surfacesconstructed around adatum axis
Surfaces constructed
perpendicular to adatum axis
Features Applicableto Runout Tolerancing
-
8/7/2019 2-GD & T
50/96
0+ -
Full IndicatorMovement
Maximum Minimum
Total
Tolerance
MaximumReading
MinimumReading
Full PartRotation
Measuring position #1(circular element #1)
Circular Runout
When measuring circular runout, the indicator must be reset to zero at each measuring positionalong the feature surface. Each individual circular element of the surface is independentlyallowed 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 characteristicssuch 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 toMMC or LMC.
-
8/7/2019 2-GD & T
51/96
o360 PartRotation
50 +/- 2o o
As Shownon Drawing
Means This:
Datum axis A
Single circularelement
Circular Runout(Angled Surface to Datum Axis)
0.75 A
A
50 +/-0.25
0+-
NOTE: Circular runout in this example onlycontrols the 2-dimensional circular elements(circularity and coaxiality) of the angled featuresurface not the entire angled feature surface
Full IndicatorMovement( )
The tolerance zone for any individual circularelement is equal to the total allowable movementof a dial indicator fixed in a position normal to thetrue geometric shape of the feature surface whenthe part is rotated 360 degrees about the datumaxis. The tolerance limit is applied independentlyto each individual measuring position along thefeature surface.
Allowable indicatorreading = 0.75 max.
When measuring circularrunout, the indicator mustbe reset when repositionedalong the feature surface.
Collet or Chuck
-
8/7/2019 2-GD & T
52/96
As Shownon Drawing
50 +/-0.25
0.75 A
Circular Runout(Surface Perpendicular to Datum Axis)
o360 Part
Rotation
0+-
Datum axis A
Single circularelement
NOTE: Circular runout in this example willonly control variation in the 2-dimensional
circular elements of the planar surface (wobbleand waviness) not the entire feature surface
The tolerance zone for any individual circularelement is equal to the total allowable movementof a dial indicator fixed in a position normal to thetrue geometric shape of the feature surface whenthe part is rotated 360 degrees about the datumaxis. The tolerance limit is applied independentlyto each individual measuring position along thefeature surface.
Means This:
Allowable indicator
reading = 0.75 max.
When measuring circular runout, the indicator mustbe reset when repositioned along the feature surface.
A
-
8/7/2019 2-GD & T
53/96
0+ -
Allowable indicatorreading = 0.75 max.
Single circular element
o360 PartRotation
Means This:
As Shownon Drawing
50 +/-0.25
0.75 A
Datum axis A
When measuring circular runout,the indicator must be reset whenrepositioned along the featuresurface.
Circular Runout(Surface Coaxial to Datum Axis)
The tolerance zone for any individual circular element is equalto the total allowable movement of a dial indicator fixed in aposition normal to the true geometric shape of the featuresurface when the part is rotated 360 degrees about the datum
axis. The tolerance limit is applied independently to eachindividual measuring position along the feature surface.
NOTE: Circular runout in this example willonly control variation in the 2-dimensionalcircular elements of the surface (circularity and
coaxiality) not the entire feature surface
A
-
8/7/2019 2-GD & T
54/96
0+ -
Allowable indicatorreading = 0.75 max.
Single circular element
o360 PartRotation
Means This:
As Shownon Drawing
0.75 A-B
Datum axis A-B
When measuring circular runout,the indicator must be reset whenrepositioned along the featuresurface.
Circular Runout(Surface Coaxial to Datum Axis)
The tolerance zone for any individual circular element is equalto the total allowable movement of a dial indicator fixed in aposition normal to the true geometric shape of the featuresurface when the part is rotated 360 degrees about the datum
axis. The tolerance limit is applied independently to eachindividual measuring position along the feature surface.
NOTE: Circular runout in this example willonly control variation in the 2-dimensionalcircular elements of the surface (circularity and
coaxiality) not the entire feature surface
Machinecenter
Machinecenter
BA
-
8/7/2019 2-GD & T
55/96
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 isequal to the total allowable movement of a dial indicator fixedin a position normal to the true geometric shape of thefeature surface when the part is located against the datum
surface and rotated 360 degrees about the datum axis. Thetolerance limit is applied independently to each individual
measuring position along the feature surface.
Means This:
A
Allowable indicatorreading = 0.75 max.
When measuring circular runout,the indicator must be reset whenrepositioned along the feature
surface.
Collet or Chuck
Stop collar
0.75 A B
Datum plane A
B
-
8/7/2019 2-GD & T
56/96
0+
Full IndicatorMovement
Total
Tolerance
MaximumReading
MinimumReading
Full PartRotation
-
0+ -
Total Runout
Maximum Minimum
When measuring total runout, the indicator is moved in a straight line along the feature surfacewhile the part is rotated about the datum axis. It is also acceptable to measure total runout byevaluating an appropriate number of individual circular elements along the surface while the partis rotated about the datum axis. Because the tolerance value is applied to the entire surface, theindicator 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 (overallorientation).
IndicatorPath
Total runout can only be applied on an
RFS basis and cannot be modified toMMC or LMC.
-
8/7/2019 2-GD & T
57/96
Full PartRotation
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 isequal to the total allowable movement of a dialindicator positioned normal to the true geometricshape of the feature surface when the part is
rotated about the datum axis and the indicator ismoved along the entire length of the feature
surface.0
+-
NOTE: Unlike circular runout, the use of total runoutwill provide 3-dimensional composite control of thecumulative 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, theindicator must not be reset whenrepositioned along the featuresurface.
(applies to the entire feature surface)Allowable indicator reading = 0.75 max.
-
8/7/2019 2-GD & T
58/96
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 examplewill provide composite control of the cumulativevariations of perpendicularity (wobble) andflatness (concavity or convexity) of the featuresurface.
The tolerance zone for the portion of the feature surfaceindicated is equal to the total allowable movement of a dialindicator positioned normal to the true geometric shape of thefeature surface when the part is rotated about the datum axisand the indicator is moved along the portion of the featuresurface within the area described by the basic dimensions.
When measuring total runout, the indicatormust not be reset when repositioned along thefeature surface.
(applies to portion of feature surface indicated)
Allowable indicator reading = 0.75 max.
-
8/7/2019 2-GD & T
59/96
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 right
angles 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 features size.11.
Total runout can control circularity, straightness, taper,
coaxiality, angularity and any other surface variation.12.
-
8/7/2019 2-GD & T
60/96
Notes
-
8/7/2019 2-GD & T
61/96
Notes
-
8/7/2019 2-GD & T
62/96
Fixed andFloating
FastenerExercises
-
8/7/2019 2-GD & T
63/96
2x M10 X 1.5(Reference)
BA
?.?
2x 10.50 +/- 0.25
M Calculate Required
Positional Tolerance
0.5
2x ??.?? +/- 0.25
M
CalculateNominal Size
A
B
T = H - FH = Minimum Hole Size = 10.25F = Max. Fastener Size = 10
T = 10.25 -10T = ______
Floating Fasteners
H = F +TF = Max. Fastener Size = 10
T = Positional Tolerance = 0.50
H = 10 + 0.50H = ______
In applications where two or more mating details are assembled, and all parts
have clearance holes for the fasteners, the floating fastener formulashownbelow 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 fastenerT= Positional tolerance diameter
H=F+T or T=H-F
General Equation Applies toEach Part Individually
remember: the size tolerance must beadded to the calculated MMC hole size toobtain the correct nominal value.
-
8/7/2019 2-GD & T
64/96
2x M10 X 1.5(Reference)
BA
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 fastenerT= Positional tolerance diameter
H=F+T or T=H-F
General Equation Applies toEach Part Individually
T = H - FH = Minimum Hole Size = 10.25F = Max. Fastener Size = 10
T = 10.25 -10T = 0.25
Calculate Required
Positional Tolerance
F = Max. Fastener Size = 10
T = Positional Tolerance = 0.5
H = 10 + .5H = 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 formulashownbelow 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 beadded to the calculated MMC hole size toobtain the correct nominal value.
CalculateNominal Size
-
8/7/2019 2-GD & T
65/96
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 RequiredClearance 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 fastenerT= Positional tolerance diameter
H=F+2T or T=(H-F)/2
General Equation Used When
Positional Tolerances Are Equal
In fixed fastenerapplications where two mating details have equal positionaltolerances, the fixed fastener formulashown below can be used to calculate theappropriate 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 tolerancemust be added to the calculatedMMC size to obtain the correct
nominal value.
10
-
8/7/2019 2-GD & T
66/96
2x M10 X 1.5(Reference)
B
A
2x 11.85 +/- 0.25
0.8 M
Calculate RequiredClearance Hole Size.
A
B
In fixed fastenerapplications where two mating details have equal positionaltolerances, the fixed fastener formulashown below can be used to calculate theappropriate 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 fastenerT= 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 tolerancemust be added to the calculatedMMC size to obtain the correct
nominal value.
REMEMBER!!! All Calculations Apply at MMC
10
-
8/7/2019 2-GD & T
67/96
2x M10 X 1.5(Reference)
B
A
2x 11.85 +/- 0.25
0.8 M
Calculate RequiredClearance Hole Size.
A
B
In fixed fastenerapplications where two mating details have equal positionaltolerances, the fixed fastener formulashown below can be used to calculate theappropriate 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
T = Positional Tolerance = 0.8
H = 10 + 2(0.8)H = 11.6 Minimum
H= Min. diameter of clearance hole
F= Maximum diameter of fastenerT= 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 tolerancemust be added to the calculatedMMC size to obtain the correct
nominal value.
REMEMBER!!! All Calculations Apply at MMC
10
-
8/7/2019 2-GD & T
68/96
2x M10 X 1.5(Reference)
B
A
0.5
2x 11.25 +/- 0.25
M Calculate RequiredPositional Tolerance .(Both Parts)
A
B
In applications where two mating details are assembled, and one part hasrestrained fasteners, the fixed fastener formulashown below can be used tocalculate 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 = 11
F = Max. Fastener Size = 10
T = (11 - 10)/2T = 0.50
H= Min. diameter of clearance hole
F= Maximum diameter of fastenerT= 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
-
8/7/2019 2-GD & T
69/96
2x M10 X 1.5(Reference)
B
A
0.5
2x ??.?? +/- 0.25
M
Calculate RequiredClearance 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 WhenPositional Tolerances Are Not Equal
F = Max. Fastener Size = 10
T1 = 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 positionaltolerances, the fixed fastener formulashown below can be used to calculate theappropriate 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 beadded to the calculated MMC hole size toobtain the correct nominal value.
10
1 M 10P
-
8/7/2019 2-GD & T
70/96
2x M10 X 1.5(Reference)
B
A
0.5
2x 11.75 +/- 0.25
M
Calculate RequiredClearance Hole Size.
A
B
In fixed fastener applications where two mating details have unequal positionaltolerances, the fixed fastener formulashown below can be used to calculate theappropriate 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 = 10
T1 = 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 WhenPositional 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 beadded to the calculated MMC hole size toobtain the correct nominal value.
REMEMBER!!! All Calculations Apply at MMC
10
-
8/7/2019 2-GD & T
71/96
D
P
H F
A
B
APPLIES WHEN A PROJECTED TOLERANCE ZONE IS NOT USED
2x 10.05 +/-0.05
B
A
0.5 M2x ??.?? +/-0.25Calculate
Nominal Size
0.5 M
In applications where a projected tolerance zone is notindicated, it isnecessary to select a positional tolerance and minimum clearance hole sizecombination that will allow for any out-of-squareness of the feature containing the
fastener. The modified fixed fastener formulashown 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 atMMC 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 toobtain the correct nominal value.
H= Min. diameter of clearance holeF= Maximum diameter of pinT1= 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 = 10
T1 = Positional Tol. (A) = 0.5T2 = Positional Tol. (B) = 0.5 D
= Min. pin depth = 20. P= Max. pin projection = 15
-
8/7/2019 2-GD & T
72/96
D
P
H F
A
B
H= Min. diameter of clearance holeF= Maximum diameter of pinT1= 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 M2x 12 +/-0.25Calculate
Nominal Size
0.5 M
F = Max. pin size = 10
T1 = 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 notindicated, it isnecessary to select a positional tolerance and minimum clearance hole sizecombination that will allow for any out-of-squareness of the feature containing the
fastener. The modified fixed fastener formulashown 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 atMMC 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 toobtain the correct nominal value.
-
8/7/2019 2-GD & T
73/96
Answers to Quizzesand Exercises
-
8/7/2019 2-GD & T
74/96
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
-
8/7/2019 2-GD & T
75/96
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
-
8/7/2019 2-GD & T
76/96
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 (CDs) 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
-
8/7/2019 2-GD & T
77/96
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-linearand 3-rotationaldegreesof freedom.
A planar primary datum plane will restrain 1-linearand 2-rotationaldegrees of freedom.
The primary and secondary datum planes together will restrain fivedegreesof freedom.
The primary, secondary and tertiary datum planes together will
restrain all sixdegrees 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 featureis an actual feature on a part.
A datumis a theoretically exact point, axis or plane.
A datum simulatoris a precise surface used to establish asimulated 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
-
8/7/2019 2-GD & T
78/96
Straightnessand circularityare individual line or circularelement (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 format MMC.
Flatnessand cylindricityare surface (3-D) controls.
Circularity can be applied to both straightand taperedcylindricalparts.
1.
2.
3.
4.
5.
Form controls require a datum reference.
Form controls do not directly control a features size.
A features form tolerance must be less than its size
tolerance.
Flatness controls the orientation of a feature.
Size limits implicitly control a features 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
-
8/7/2019 2-GD & T
79/96
Orientation Control Quiz
The three orientation controls are angularity, parallelism,and perpendicularity.
1.
2.
3.
4.
5.
A datum referenceis always required when applying any ofthe orientation controls.
Perpendicularityis the appropriate geometric tolerance when
controlling the orientation of a feature at right angles to a datumreference.
Orientation tolerances indirectly control a features form.
Mathematically all three orientation tolerances are identical.
Orientation tolerances do not control the locationof 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 must
be 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
-
8/7/2019 2-GD & T
80/96
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 right
angles 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 features size.11.
Total runout can control circularity, straightness, taper,
coaxiality, angularity and any other surface variation.12. TRUE
FALSE
TRUE
TRUE
FALSE
-
8/7/2019 2-GD & T
81/96
In composite profile applications, the tolerance shown in the upper
segment of the feature control frame applies only to the locationof thefeature.
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 bilateralor unilateral.
Profile of a linetolerances are 2-dimensional controls.
Profile of a surfacetolerances are 3-dimensional controls.
Questions #1-9 Fill in blanks (choose from below)
6. Composite Profilecan be used when different tolerances arerequired for location and form and/or orientation.
7. When using profile tolerances to control the location and/or orientation of
a feature, a datum referencemust be included in the feature controlframe.
8. When using profile tolerances to control form only, a datumreferenceis 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
-
8/7/2019 2-GD & T
82/96
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 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 afeature to the specified datums.
13.
TRUE
FALSE
FALSE
FALSE
TRUE
TRUE
TRUE
FALSE
FALSE
FALSE
TRUE
TRUE
FALSE
-
8/7/2019 2-GD & T
83/96
True Position Quiz
Answer questions #1-11 True or False
TRUE
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 features size.
Positional tolerances are applied on an MMC, LMC, orRFS basis.
2.
3.
4.
5.
FALSE
True position tolerance values are used to calculate the
minimum size of a feature required for assembly.
TRUE
TRUE
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 specifieddatums.
8. TRUE
Positional tolerances can be used to control circularity
9. FALSE
10.
11. TRUE
FALSE
TRUE
FALSE
TRUE
The tolerance value shown in the lower segment of acomposite true position feature control frame applies
to the location of a pattern of features to the specifieddatums.
True position tolerances can be used to control center
distance relationships between features of size.
-
8/7/2019 2-GD & T
84/96
Positional tolerance zones can be rectangular, cylindrical,or spherical
1.
2.
3.
4.
5.
Basic dimensionsare used to establish the true (theoreticallyexact) position of a feature from specified datums.
Positional tolerancing is a 3-dimensionalcontrol.
Positional tolerance can apply to the axisor surface boundaryof a feature.
Fixedand floatingfastener equations are used to determineappropriate clearance hole sizes for mating details
6.
7.
Projectedtolerance zones are recommended to prevent fastenerinterference 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 trueposition 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 maximummaterialcondition is specified
axis
-
8/7/2019 2-GD & T
85/96
Virtual andResultant
ConditionBoundaries
Internal and ExternalFeatures (MMC Concept)
-
8/7/2019 2-GD & T
86/96
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 ofMMC Hole Shownat Extreme Limit
Boundary of MMC HoleShown at Extreme Limit
1 PositionalTolerance Zone at
MMC
True (Basic)Position of Hole
True (Basic)Position of Hole
Other PossibleExtreme Locations
Virtual ConditionInner Boundary
Maximum Inscribed
Diameter( )
-
8/7/2019 2-GD & T
87/96
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 ofLMC Hole Shownat Extreme Limit
Boundary of LMC HoleShown at Extreme Limit
2 PositionalTolerance Zone at
LMC
True (Basic)Position of Hole
True (Basic)Position of Hole
Other PossibleExtreme Locations
Resultant ConditionOuter Boundary
Minimum CircumscribedDiameter( )
-
8/7/2019 2-GD & T
88/96
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 ofMMC Feature Shownat Extreme Limit
Boundary of MMC FeatureShown at Extreme Limit
1 PositionalTolerance Zone at
MMC
True (Basic)Position of Feature
True (Basic)Position of Feature
Other PossibleExtreme Locations
Virtual ConditionOuter Boundary
Minimum CircumscribedDiameter( )
-
8/7/2019 2-GD & T
89/96
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 ofLMC Feature Shownat Extreme Limit
Boundary of LMC featureShown at Extreme Limit
2 PositionalTolerance Zone at
LMC
True (Basic)Position of Feature
True (Basic)
Position of Feature
Other PossibleExtreme Locations
Resultant ConditionInner Boundary
Maximum Inscribed
Diameter( )
-
8/7/2019 2-GD & T
90/96
Extreme Variations of Form
Allowed By Size Tolerance25.125
25(MMC)
25.1(LMC)
25.1(LMC)
25(MMC)
25.1(LMC)
MMC PerfectForm Boundary
Internal Feature of Size
-
8/7/2019 2-GD & T
91/96
Extreme Variations of Form
Allowed By Size Tolerance25
24.9
25
(MMC)24.9(LMC)
24.9(LMC)
MMC PerfectForm Boundary
25
(MMC)
24.9(LMC)
External Feature of Size
-
8/7/2019 2-GD & T
92/96
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 PerfectForm Boundary
25(MMC)
24.9
(LMC)
-
8/7/2019 2-GD & T
93/96
EN
D
-
8/7/2019 2-GD & T
94/96
Notes
-
8/7/2019 2-GD & T
95/96
Notes
-
8/7/2019 2-GD & T
96/96
Notes