21917046 machining symbols
TRANSCRIPT
Based on the ASME Y14.5MBased on the ASME Y14.5M--
1994 Dimensioning and 1994 Dimensioning and
Tolerancing StandardTolerancing Standard
DIMENSIONAL
ENGINEERING
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)
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
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
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
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.
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.
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.
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
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.
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
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.
____________ 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
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)
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
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
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
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.
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.
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
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.
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
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
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
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
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)
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
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.
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
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
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
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
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
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.
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.
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.
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.
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)
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.
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
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.
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
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
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
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
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.
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
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)
Notes
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
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)
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)
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
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
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
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)
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
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
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
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.
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
Notes
Notes
Fixed and
Floating
Fastener
Exercises
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.
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
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
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
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
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
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
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
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
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.
Answers to Quizzes
and Exercises
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
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
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
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
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
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
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
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
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
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.
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
E
N
D
Notes
Notes
Notes
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)
Virtual and
Resultant
Condition
Boundaries
Internal and External
Features (MMC Concept)
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( )
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( )
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( )
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( )