No Slide Title

Transcript No Slide Title

DIMENSIONAL ENGINEERING

Based on the ASME Y14.5M 1994 Dimensioning and Tolerancing Standard

INTRODUCTION

Geometric dimensioning and tolerancing (GD&T) is an international engineering language that is used on engineering drawings (blue prints) to describe product in three dimensions. GD&T uses a series of internationally recognized symbols rather than words to describe the product. These symbols are applied to the features of a part and provide a very concise and clear definition of design intent.

GD&T is a very precise mathematical language that describes the form, orientation and location of part features in zones of tolerance. These zones of tolerance are then described relative to a Cartesian coordinate system.

ASME Y14.5M-1994 American national Standards Institute/

American Society of Mechanical Engineers

Tolerances of Form

Straightness

(ASME Y14.5M-1994, 6.4.1)

Flatness

(ASME Y14.5M-1994, 6.4.2)

Circularity

(ASME Y14.5M-1994, 6.4.3)

Cylindricity

(ASME Y14.5M-1994, 6.4.4)

Extreme Variations of Form Allowed By Size Tolerance

25.1 25 25 (MMC) 25 (MMC) 25.1 (LMC) 25.1 (LMC) MMC Perfect Form Boundary 25.1 (LMC)

Internal Feature of Size

Extreme Variations of Form Allowed By Size Tolerance

25 24.9

24.9 (LMC) MMC Perfect Form Boundary 25 (MMC) 24.9 (LMC) 25 (MMC) 24.9 (LMC)

External Feature of Size

25 +/-0.25

Straightness

(Flat Surfaces)

0.5

0.1

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 Tolerance Zone 24.75 min 0.1 Tolerance Zone 25.25 max

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.

The straightness tolerance is applied in the view where the elements to be controlled are represented by a straight line

Straightness

(Surface Elements)

0.1

0.1 Tolerance Zone MMC 0.1 Tolerance Zone MMC 0.1 Tolerance Zone MMC

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)

0.1

MMC 0.1 Diameter Tolerance Zone Outer Boundary (Max) Outer 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

0.1

M 15 (MMC) 0.1 Diameter Tolerance Zone 15.1 Virtual Condition 14.85 (LMC) 0.25 Diameter Tolerance Zone 15.1 Virtual Condition

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.

Flatness

0.1

25 +/-0.25

0.1 Tolerance Zone 24.75 min 0.1 Tolerance Zone 25.25 max

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.

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.

Circularity

(Roundness)

0.1

90 90 0.1 Wide Tolerance Zone

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.

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

Cylindricity

0.1

0.1 Tolerance Zone MMC

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.

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.

Form Control Quiz

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

The four form controls are

____________

________

___________

, and

____________

. 2.

Rule #1 states that unless otherwise specified a feature of size must have

____________

at MMC.

____________

and

___________

are individual line or circular element (2-D) controls.

________

and

____________

are surface (3-D) controls.

Circularity can be applied to both

________

and

_______

cylindrical parts.

straightness straight perfect form cylindricity flatness tapered circularity angularity profile true position

Answer questions #6-10 True or False 6.

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 size tolerance.

Flatness controls the orientation of a feature.

10.

Size limits implicitly control a feature’s form.

Tolerances of Orientation

Angularity

(ASME Y14.5M-1994 ,6.6.2)

Perpendicularity

(ASME Y14.5M-1994 ,6.6.4)

Parallelism

(ASME Y14.5M-1994 ,6.6.3)

Angularity

(Feature Surface to Datum Surface)

20 +/-0.5

0.3 A 30 o

A

19.5 min 20.5 max 30 o 30 o

A

0.3 Wide Tolerance Zone

A

0.3 Wide Tolerance Zone

The tolerance zone in this example is defined by two parallel planes oriented at the specified angle to the datum reference plane.

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.

Angularity

(Feature Axis to Datum Surface)

NOTE: Tolerance applies to feature at RFS

0.3 A 0.3 Circular Tolerance Zone 0.3 Circular Tolerance Zone 60 o

A

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.

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.

Angularity

(Feature Axis to Datum Axis)

NOTE: Feature axis must lie within tolerance zone cylinder

A

0.3 Circular Tolerance Zone 0.3 A

NOTE: Tolerance applies to feature at RFS

0.3 Circular Tolerance Zone 45 o Datum Axis A

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.

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.

Perpendicularity

(Feature Surface to Datum Surface)

0.3 A

A

0.3 Wide Tolerance Zone 0.3 Wide Tolerance Zone

A

The tolerance zone in this example is defined by two parallel planes oriented perpendicular to the datum reference plane.

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 Axis to Datum Surface)

0.3 Diameter Tolerance Zone 0.3 Circular Tolerance Zone

C

0.3 C

NOTE: Tolerance applies to feature at RFS

0.3 Circular Tolerance Zone

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 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 Axis)

NOTE: Tolerance applies to feature at RFS

0.3 A

A

0.3 Wide Tolerance Zone Datum Axis A

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.

Parallelism

(Feature Surface to Datum Surface)

25 +/-0.5

A

0.3 Wide Tolerance Zone 0.3 A 0.3 Wide Tolerance Zone 25.5 max 24.5 min

A

The tolerance zone in this example is defined by two parallel planes oriented parallel to the datum reference plane.

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 Axis to Datum Surface)

NOTE: The specified tolerance does not apply to the orientation of the feature axis in this direction NOTE: Tolerance applies to feature at RFS

0.3 A 0.3 Wide Tolerance Zone

A

The tolerance zone in this example is defined by two parallel planes oriented parallel to the datum reference plane.

A

Parallelism is the condition of the feature axis equidistant along its length from the datum reference plane, within the specified tolerance zone.

B

Parallelism

(Feature Axis to Datum Surfaces)

0.3 Circular Tolerance Zone 0.3 Circular Tolerance Zone 0.3 A B

NOTE: Tolerance applies to feature at RFS

0.3 Circular Tolerance Zone

B 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 planes.

A

Parallelism is the condition of the feature axis equidistant along its length from the two datum reference planes, within the specified tolerance zone.

Parallelism

(Feature Axis to Datum Axis)

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

0.1 Circular Tolerance Zone 0.1 A

A

0.1 Circular Tolerance Zone Datum Axis A Parallelism is the condition of the feature axis equidistant along its length from the datum reference axis, within the specified tolerance zone.

Orientation Control Quiz

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

The three orientation controls are

__________

___________

, and

________________

. 2.

_______________

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 datum reference.

Mathematically all three orientation tolerances are

_________

Orientation tolerances do not control the

________

of a feature.

perpendicularity datum feature angularity datum target location identical datum reference parallelism profile

Answer questions #6-10 True or False 6.

Orientation tolerances indirectly control a feature’s form.

Orientation tolerance zones can be cylindrical.

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

Parallelism tolerances do not apply to features of size.

10.

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

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)

Features Applicable to Runout Tolerancing

Internal surfaces constructed around a datum axis External surfaces constructed around a datum axis Datum axis (established from datum feature Datum feature Angled surfaces constructed around a datum axis

Surfaces constructed perpendicular to a datum axis

Circular Runout

Maximum Full Indicator Movement Maximum Reading + 0 Minimum Reading Total Tolerance

Circular runout can only be applied on an RFS basis and cannot be modified to MMC or LMC.

Minimum Measuring position #1 (circular element #1) Full Part Rotation Measuring position #2 (circular element #2)

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).

Circular Runout

(Angled Surface to Datum Axis)

0.75 A A 50 +/-0.25

Means This:

Allowable indicator reading = 0.75 max.

(

Full Indicator Movement

)

0 + When measuring circular runout, the indicator must be reset when repositioned along the feature surface.

50 +/- 2 o

As Shown on Drawing

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.

Collet or Chuck Datum axis A Single circular element Rotation

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

Circular Runout

(Surface Perpendicular to Datum Axis)

0.75 A A 50 +/-0.25

Means This:

Single circular element Rotation

As Shown on Drawing

0 + When measuring circular runout, the indicator must be reset when repositioned along the feature surface.

Allowable indicator reading = 0.75 max.

Datum axis A

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

Circular Runout

(Surface Coaxial to Datum Axis)

0.75 A A 50 +/-0.25

As Shown on Drawing Means This:

Allowable indicator reading = 0.75 max.

+ 0 When measuring circular runout, the indicator must be reset when repositioned along the feature surface.

Single circular element Datum axis A Rotation

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

Circular Runout

(Surface Coaxial to Datum Axis)

0.75 A-B A B

As Shown on Drawing Means This:

Allowable indicator reading = 0.75 max.

+ 0 When measuring circular runout, the indicator must be reset when repositioned along the feature surface.

Machine center Single circular element Datum axis A-B Rotation Machine center

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

Circular Runout

(Surface Related to Datum Surface and Axis)

0.75 A B A B 50 +/-0.25

As Shown on Drawing Means This:

Allowable indicator reading = 0.75 max.

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.

Single circular element Stop collar + 0 Collet or Chuck Rotation Datum axis B When measuring circular runout, the indicator must be reset when repositioned along the feature surface.

Datum plane A

Total Runout

Maximum Full Indicator Movement Maximum Reading + 0 Minimum Reading Total Tolerance

Total runout can only be applied on an RFS basis and cannot be modified to MMC or LMC.

Minimum Indicator Path + 0 Full Part Rotation

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).

Total Runout

(Angled Surface to Datum Axis)

0.75 A A 50 +/-0.25

Means This:

When measuring total runout, the indicator must not be reset when repositioned along the feature surface.

0 + 0 + 50 +/- 2 o

As Shown on Drawing

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.

Allowable indicator reading = 0.75 max.

(applies to the entire feature surface) Collet or Chuck Full Part Rotation Datum axis A

NOTE: Unlike circular runout, the use of total runout will provide 3-dimensional composite control of the cumulative variations of circularity, coaxiality, angularity, taper and profile of the angled surface

Total Runout

(Surface Perpendicular to Datum Axis)

0.75 A 10 35 50 +/-0.25

As Shown on Drawing Means This:

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.

10 35 Full Part Rotation 0 + 0 + When measuring total runout, the indicator must not be reset when repositioned along the feature surface.

Allowable indicator reading = 0.75 max.

(applies to portion of feature surface indicated) Datum axis A

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.

Runout Control Quiz

Answer questions #1-12 True or False 1.

Total runout is a 2-dimensional control.

Runout tolerances are used on rotating parts.

Circular runout tolerances apply to single elements .

Total runout tolerances should be applied at MMC.

Runout tolerances can be applied to surfaces at right angles to the datum reference. 6.

Circular runout tolerances are used to control an entire feature surface.

Runout tolerances always require a datum reference.

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

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

10.

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

11.

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

12.

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

Tolerances of Profile

Profile of a Line

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

Profile of a Surface

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

Profile of a Line

20 X 20 A1 B A3 20 X 20 20 X 20 A2 1 A B C C 17 +/- 1 2 Wide

Size

Tolerance Zone 18 Max A 1 Wide

Profile

Tolerance Zone 16 Min.

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.

Profile of a Surface

20 X 20 A1 B A3 20 X 20 20 X 20 A2 A C 2 A B C 23.5

2 Wide Tolerance Zone

Size, Form and Orientation

23.5

Nominal 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.

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

(Bilateral Tolerance)

20 X 20 A1 B 20 X 20 A3 20 X 20 A2 1 A B C C 50 1 Wide Total Tolerance Zone B 0.5 Inboard 0.5 Outboard C 50 Nominal Location

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.

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

(Unilateral Tolerance)

20 X 20 A1 B 20 X 20 A3 20 X 20 A2 0.5 A B C C 50 0.5 Wide Total Tolerance Zone B C 50 Nominal Location

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.

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.

Profile of a Surface

(Unequal Bilateral Tolerance)

20 X 20 A1 B 20 X 20 A3 20 X 20 A2 0.5

1.2 A B C C 50 1.2 Wide Total Tolerance Zone B 0.5 Inboard 0.7 Outboard C 50 Nominal Location

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.

Profile of a Surface

0.5

0.1

A Location & Orientation Form Only 25 A 25.25

0.1 Wide Tolerance Zone 24.75

Composite Profile of Two Coplanar Surfaces w/o Orientation Refinement

Profile of a Surface

0.5

0.1

A A Location Form & Orientation 25 25.25

A 0.1 Wide Tolerance Zone 24.75

A 0.1 Wide Tolerance Zone A

Composite Profile of Two Coplanar Surfaces With Orientation Refinement

Profile Control Quiz

Answer questions #1-13 True or False 1.

Profile tolerances always require a datum reference.

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

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

Profile of a line tolerances should be applied at MMC.

Profile tolerances can be applied to features of size.

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.

Profile of a line controls apply to individual line elements.

Profile tolerances only control the location of a surface.

10.

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

11.

Profile tolerances can be applied either bilateral or unilateral to a feature.

12.

Profile tolerances can be applied in both freestate and restrained datum conditions.

13.

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

Profile Control Quiz

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

The two types of profile tolerances are

_________________

, and

____________________.

Profile tolerances can be used to control the

________

____

___________

, and sometimes size of a feature.

Profile tolerances can be applied

_________

__________.

_________________

tolerances are 2-dimensional controls.

____________________

tolerances are 3-dimensional controls.

_________________

can be used when different tolerances are required for location and form and/or orientation.

When using profile tolerances to control the location and/or orientation of a feature, a

_______________

must be included in the feature control frame.

When using profile tolerances to control form only, a

______ __________

is not required in the feature control frame.

In composite profile applications, the tolerance shown in the upper segment of the feature control frame applies only to the

________

the feature.

composite profile profile of a surface bilateral virtual condition primary datum orientation datum reference location unilateral profile of a line true geometric counterpart form

Tolerances of Location

True Position

(ASME Y14.5M-1994, 5.2)

Concentricity

(ASME Y14.5M-1994, 5.12) Symmetry (ASME Y14.5M-1994, 5.13)

Notes

Coordinate vs Geometric Tolerancing Methods

8.5 +/- 0.1

Rectangular Tolerance Zone

10.25 +/- 0.5

8.5 +/- 0.1

1.4 A B C Circular Tolerance Zone 10.25

B 10.25

C 10.25 +/- 0.5

Coordinate Dimensioning +/- 0.5

Geometric Dimensioning 1.4

+/- 0.5

Rectangular Tolerance Zone Circular Tolerance Zone

57% Larger Tolerance Zone

Circular Tolerance Zone

Rectangular Tolerance Zone

Increased Effective Tolerance

Positional Tolerance Verification

(Applies when a circular tolerance is indicated)

X

Z

Feature axis actual location (measured) Positional tolerance zone cylinder Actual feature boundary

Y

Feature axis true position (designed)

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

Z = X

+ Y

Z positional tolerance /2 Z = total radial deviation “X” measured deviation “Y” measured deviation

Positional Tolerance Verification

(Applies when a circular tolerance is indicated)

X

Z

Feature axis actual location (measured) Positional tolerance zone cylinder Actual feature boundary

Y

Feature axis true position (designed)

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

Z = X

+ Y

Z +( actual 2 = positional tolerance MMC) Z = total radial deviation “X” measured deviation “Y” measured deviation

Bi-directional True Position Rectangular Coordinate Method

2X 1.5 A B C 2X 0.5 A B C C A 10 10 35 2X 6 +/-0.25

Means This:

1.5 Wide Tolerance Zone C B

As Shown on Drawing

True Position Related to Datum Reference Frame 10 10 35 B 0.5 Wide Tolerance Zone Each axis must lie within the 1.5 X 0.5 rectangular tolerance zone basically located to the datum reference frame

Bi-directional True Position Multiple Single-Segment Method

2X 6 +/-0.25

1.5 A B C 0.5 A B C A 10 10 35

Means This:

1.5 Wide Tolerance Zone C B

As Shown on Drawing

True Position Related to Datum Reference Frame 10 10 35 B 0.5 Wide Tolerance Zone Each axis must lie within the 1.5 X 0.5 rectangular tolerance zone basically located to the datum reference frame

Bi-directional True Position Noncylndrical Features (Boundary Concept)

2X 13 +/-0.25

BOUNDARY 2X 6 +/-0.25

BOUNDARY C A 10 10 35 B

As Shown on Drawing Means This:

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.

True position boundary related to datum reference frame C 5.75 MMC length of slot -0.50

Position tolerance 5.25 maximum boundary 12.75

-1.50

MMC width of slot Position tolerance 11.25 Maximum boundary 90 o 10 A 10 35 B

Composite True Position Without Pattern Orientation Control

2X 6 +/-0.25

1.5 A B C 0.5 A C A 10 10 35

Means This:

0.5 Feature-Relating Tolerance Zone Cylinder

pattern orientation relative to Datum A only (perpendicularity)

C B

As Shown on Drawing

1.5 Pattern-Locating Tolerance Zone Cylinder

pattern location relative to Datums A, B, and C

10 10 35 B True Position Related to Datum Reference Frame Each axis must lie within each tolerance zone simultaneously

Composite True Position With Pattern Orientation Control

2X 6 +/-0.25

1.5 A B C 0.5 A B C A 10 10 35

Means This:

True Position Related to Datum Reference Frame C B

As Shown on Drawing

1.5 Pattern-Locating Tolerance Zone Cylinder

pattern location relative to Datums A, B, and C

10 10 35 B 0.5 Feature-Relating Tolerance Zone Cylinder

pattern orientation relative to Datums A and B

Each axis must lie within each tolerance zone simultaneously

Location (Concentricity) Datum Features at RFS

6.35 +/- 0.05

0.5 A A 15.95

15.90

As Shown on Drawing

Means This:

Axis of Datum Feature A 0.5 Coaxial Tolerance Zone Derived Median Points of Diametrically Opposed Elements 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.

Location (Symmetry) Datum Features at RFS

6.35 +/- 0.05

0.5 A 15.95

15.90

Means This:

As Shown on Drawing

Center Plane of Datum Feature A 0.5 Wide Tolerance Zone Derived Median Points 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.

True Position Quiz

Answer questions #1-11 True or False 1.

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

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

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

True position tolerances can control a feature’s size.

Positional tolerances are applied on an MMC, LMC, or RFS basis.

Composite true position tolerances should be avoided because it is overly restrictive and difficult to check.

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

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.

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.

10.

Positional tolerances can be used to control circularity 11.

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

True Position Quiz

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

Positional tolerance zones can be

___________

, or spherical 2.

________________

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

____

a feature.

________________

of 5.

_____

and

________

fastener equations are used to determine appropriate clearance hole sizes for mating details 6.

_________

tolerance zones are recommended to prevent fastener interference in mating details.

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.

Functional gaging principles can be applied when

__________ ________

condition is specified

surface boundary pattern-locating floating rectangular feature-relating cylindrical 3-dimensional location basic dimensions maximum material

axis

projected fixed

Notes

Fixed and Floating Fastener Exercises

Floating Fasteners

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 2x M10 X 1.5

(Reference) A B

General Equation Applies to Each Part Individually

H=F+T or T=H-F

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

2x 10.50

?.?

M +/- 0.25

Calculate Nominal Size

A B 2x

Calculate Required Positional Tolerance

T = H - F

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

+/- 0.25

0.5

remember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

H = F +T

F = Max. Fastener Size = 10 T = Positional Tolerance = 0.50

H = 10 + 0.50 H = ______

Floating Fasteners

In applications where two or more mating details are assembled, and all parts have clearance holes for the fasteners, the

floating fastener formula

(Reference) A B

General Equation Applies to Each Part Individually

H=F+T or T=H-F

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

2x 10.50

0.25

M +/- 0.25

Calculate Nominal Size

A B 2x

Calculate Required Positional Tolerance

T = H - F

H = Minimum Hole Size = 10.25 F = Max. Fastener Size = 10 T = 10.25 -10 T = 0.25

10.75

+/- 0.25

0.5

remember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

H = F +T

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

H = 10 + .5 H = 10.5 Minimum

REMEMBER!!! All Calculations Apply at MMC

Fixed Fasteners

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.) 10 APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED 2x M10 X 1.5

(Reference) A B

General Equation Used When Positional Tolerances Are Equal

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

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

Calculate Required Clearance Hole Size.

2x ??.??

+/- 0.25

0.8

remember: the size tolerance must be added to the calculated MMC size to obtain the correct nominal value.

2X M10 X 1.5

0.8

M P 10 A

Nominal Size (MMC For Calculations)

H = F + 2T

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

H = 10.00 + 2(0.8) H = _____ B

Fixed Fasteners

fixed fastener

applications where two mating details have equal positional tolerances, the

fixed fastener formula

(Reference) A B

General Equation Used When Positional Tolerances Are Equal

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

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

Calculate Required Clearance Hole Size.

2x 11.85

+/- 0.25

0.8

remember: the size tolerance must be added to the calculated MMC size to obtain the correct nominal value.

2X M10 X 1.5

0.8

M P 10 A

Nominal Size (MMC For Calculations)

H = F + 2T

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

H = 10.00 + 2(0.8) H = 11.60 Minimum B

REMEMBER!!! All Calculations Apply at MMC

Fixed Fasteners

fixed fastener

applications where two mating details have equal positional tolerances, the

fixed fastener formula

(Reference) A B

General Equation Used When Positional Tolerances Are Equal

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

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

Calculate Required Clearance Hole Size.

2x 11.85

+/- 0.25

0.8

remember: the size tolerance must be added to the calculated MMC size to obtain the correct nominal value.

2X M10 X 1.5

0.8

M P 10 A

Nominal Size (MMC For Calculations)

H = F + 2T

F = Max. Fastener Size = 10 T = Positional Tolerance = 0.8

H = 10 + 2(0.8) H = 11.6 Minimum B

REMEMBER!!! All Calculations Apply at MMC

Fixed Fasteners

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.) 10 APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED 2x M10 X 1.5

(Reference) A B

General Equation Used When Positional Tolerances Are Equal

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

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

2x 11.25

0.5

M +/- 0.25

Calculate Required Positional Tolerance . (Both Parts)

Nominal Size (MMC For Calculations)

2X M10 X 1.5

0.5

M P 10

T = (H - F)/2

H = Minimum Hole Size = 11 F = Max. Fastener Size = 10 T = (11 - 10)/2 T = 0.50

REMEMBER!!! All Calculations Apply at MMC

Fixed Fasteners

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.) 10 APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED 2x M10 X 1.5

(Reference) A B

General Equation Used When Positional Tolerances Are Not Equal

H=F+(T

+ T

)

H = Min. diameter of clearance hole F = Maximum diameter of fastener T 1 = Positional tolerance (Part A) T 2 = Positional tolerance (Part B)

Calculate Required Clearance Hole Size.

2x ??.??

+/- 0.25

0.5

remember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

A 2X M10 X 1.5

1 M P 10

Nominal Size (MMC For Calculations)

H=F+(T

+ T

)

F = Max. Fastener Size = 10 T 1 = Positional Tol. (A) = 0.50 T 2 = Positional Tol. (B) = 1 H = 10+ (0.5 + 1) H = ____ B

Fixed Fasteners

fixed fastener

applications where two mating details have unequal positional tolerances, the

fixed fastener formula

(Reference) A B

General Equation Used When Positional Tolerances Are Not Equal

H= F+(T

+ T

)

H = Min. diameter of clearance hole F = Maximum diameter of fastener T 1 = Positional tolerance (Part A) T 2 = Positional tolerance (Part B)

Calculate Required Clearance Hole Size.

2x 11.75

+/- 0.25

0.5

remember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

2X M10 X 1.5

1 M P 10 A

Nominal Size (MMC For Calculations)

H=F+(T

+ T

)

F = Max. Fastener Size = 10 T 1 = Positional Tol. (A) = 0.5 T 2 = Positional Tol. (B) = 1 H = 10 + (0.5 + 1) H = 11.5 Minimum B

REMEMBER!!! All Calculations Apply at MMC

Fixed Fasteners

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.

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS NOT USED H F P D A B H= Min. diameter of clearance hole F= Maximum diameter of pin T 1 = Positional tolerance (Part A) T 2 = Positional tolerance (Part B) D= Min. depth of pin (Part A) P= Maximum projection of pin

Calculate Nominal Size

2x ??.?? +/-0.25

0.5

remember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

A 2x 10.05 +/-0.05

0.5

M B

H= F + T

+ T

(1+(2P/D))

F = Max. pin size = 10 T 1 = Positional Tol. (A) = 0.5

T 2 = Positional Tol. (B) = 0.5 D = Min. pin depth = 20. P = Max. pin projection = 15 H = 10.00 + 0.5 + 0.5(1 + 2(15/20)) H = __________

Fixed Fasteners

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

APPLIES WHEN A PROJECTED TOLERANCE ZONE IS NOT USED P D H A B F

H= F + T

+ T

(1+(2P/D))

H= Min. diameter of clearance hole F= Maximum diameter of pin T 1 = Positional tolerance (Part A) T 2 = Positional tolerance (Part B) D= Min. depth of pin (Part A) P= Maximum projection of pin

Calculate Nominal Size

2x 12 +/-0.25

0.5

remember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

A 2x 10.05 +/-0.05

0.5

M B

H= F + T

+ T

(1+(2P/D))

F = Max. pin size = 10 T 1 = Positional tol. (A) = 0.5

T 2 = Positional tol. (B) = 0.5 D = Min. pin depth = 20 P = Max. pin projection = 15 H = 10 + 0.5 + 0.5(1 + 2(15/20)) H = 11.75 Minimum

REMEMBER!!! All Calculations Apply at MMC

Answers to Quizzes and Exercises

Rules and Definitions Quiz

Questions #1-12 True or False 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 FALSE TRUE FALSE

Material Condition Quiz

Fill in blanks

Internal Features 10.75 +0.25/-0 23.45 +0.05/-0.25

123. 5 +/-0.1

.895

.890

External Features 10.75 +0/-0.25

23.45 +0.05/-0.25

123. 5 +/-0.1

.890

.885

MMC LMC

10.75 11 23.2 23.5

123.4 123.6

.890 .895

MMC LMC

10.75 10.5

23.5 23.2

123.6 123.4

.890 .885

Calculate appropriate values

Datum Quiz

Questions #1-12 True or False 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.

7. Datums are actual part features.

8. All datum features must be dimensionally stable.

9. Datum planes constrain degrees of freedom.

10. Tertiary datums are not always required.

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

12. Datums should represent functional features.

FALSE FALSE

FALSE FALSE TRUE TRUE FALSE TRUE TRUE TRUE FALSE TRUE

Datum Quiz

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

The three planes that make up a basic datum reference frame are called

primary

secondary

, and

tertiary

. 2.

An unrestrained part will exhibit

3-linear

of freedom.

and

3-rotational

degrees 3.

A planar primary datum plane will restrain

1-linear

degrees of freedom.

and

2-rotational

The primary and secondary datum planes together will restrain

five

of freedom.

degrees 5.

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 movement

of a part in a gage or tool.

A datum must be

functional

repeatable

, and

coordinated

datum feature

is an actual feature on a part.

datum

is a theoretically exact point, axis or plane.

10.

datum simulator

simulated datum.

is a precise surface used to establish a

restrain movement tertiary three two functional datum feature five 3-rotational one datum coordinated primary datum simulator secondary repeatable 2-rotational 1-linear 3-linear six

Form Control Quiz

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

The four form controls are

straightness

flatness

circularity

, and

cylindricity

. 2.

Rule #1 states that unless otherwise specified a feature of size must have

perfect form

at MMC.

Straightness

and

circularity

element (2-D) controls.

are individual line or circular 4.

Flatness

and

cylindricity

are surface (3-D) controls.

Circularity can be applied to both

straight

parts.

and

tapered

cylindrical

straightness straight perfect form cylindricity flatness tapered circularity angularity profile true position

Answer questions #6-10 True or False 6.

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 size tolerance.

Flatness controls the orientation of a feature.

10.

Size limits implicitly control a feature’s form.

FALSE TRUE TRUE FALSE TRUE

Orientation Control Quiz

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

The three orientation controls are

angularity

parallelism

, and

perpendicularity

. 2.

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 datum reference.

Mathematically all three orientation tolerances are

identical

Orientation tolerances do not control the

location

of a feature.

perpendicularity datum feature angularity datum target location identical datum reference parallelism profile

Answer questions #6-10 True or False 6.

Orientation tolerances indirectly control a feature’s form.

Orientation tolerance zones can be cylindrical.

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

Parallelism tolerances do not apply to features of size.

10.

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

TRUE TRUE FALSE FALSE TRUE

Runout Control Quiz

Answer questions #1-12 True or False 1.

Total runout is a 2-dimensional control.

Runout tolerances are used on rotating parts.

Circular runout tolerances apply to single elements .

Total runout tolerances should be applied at MMC.

Runout tolerances can be applied to surfaces at right angles to the datum reference. 6.

Circular runout tolerances are used to control an entire feature surface.

Runout tolerances always require a datum reference.

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

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

10.

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

11.

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

12.

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

FALSE TRUE TRUE FALSE TRUE FALSE TRUE TRUE FALSE TRUE FALSE TRUE

Profile Control Quiz

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

The two types of profile tolerances are

profile of a line

, and

profile of a surface .

Profile tolerances can be used to control the

location

form

orientation

, and sometimes size of a feature.

Profile tolerances can be applied

bilateral

unilateral

Profile of a line

tolerances are 2-dimensional controls.

Profile of a surface

tolerances are 3-dimensional controls.

Composite Profile

can be used when different tolerances are required for location and form and/or orientation.

When using profile tolerances to control the location and/or orientation of a feature, a

datum reference

frame.

must be included in the feature control 8.

When using profile tolerances to control form only, a

datum reference

is not required in the feature control frame.

In composite profile applications, the tolerance shown in the upper segment of the feature control frame applies only to the

location

feature.

of the

composite profile profile of a surface bilateral virtual condition primary datum orientation datum reference location unilateral profile of a line true geometric counterpart form

Profile Control Quiz

Answer questions #1-13 True or False 1.

Profile tolerances always require a datum reference.

FALSE

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

FALSE

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

Profile of a line tolerances should be applied at MMC.

TRUE FALSE

Profile tolerances can be applied to features of size.

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

TRUE

Profile of a line tolerances apply to an entire surface.

FALSE

Profile of a line controls apply to individual line elements.

TRUE TRUE

Profile tolerances only control the location of a surface.

FALSE

10.

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

FALSE

11.

Profile tolerances can be applied either bilateral or unilateral to a feature.

TRUE

12.

Profile tolerances can be applied in both freestate and restrained datum conditions.

TRUE

13.

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

FALSE

True Position Quiz

Answer questions #1-11 True or False 1.

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

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

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

True position tolerances can control a feature’s size.

Positional tolerances are applied on an MMC, LMC, or RFS basis.

Composite true position tolerances should be avoided because it is overly restrictive and difficult to check.

TRUE TRUE TRUE FALSE TRUE FALSE

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

TRUE TRUE

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.

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.

10.

Positional tolerances can be used to control circularity 11.

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

FALSE FALSE TRUE

True Position Quiz

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

Positional tolerance zones can be

rectangular

cylindrical

, or spherical 2.

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

of a feature.

surface boundary

Fixed

and

floating

fastener equations are used to determine appropriate clearance hole sizes for mating details 6.

Projected

tolerance zones are recommended to prevent fastener interference in mating details.

The tolerance shown in the upper segment of a composite true position feature control frame is called the

pattern-locating

tolerance zone.

The tolerance shown in the lower segment of a composite true position feature control frame is called the

feature-relating

tolerance zone.

Functional gaging principles can be applied when

maximum material

condition is specified

surface boundary pattern-locating floating rectangular feature-relating cylindrical 3-dimensional location basic dimensions maximum material

axis

projected fixed

E N D

Notes

Extreme Variations of Form Allowed By Size Tolerance

25.1 25 25 24.9

25 (MMC) 25 (MMC) 25.1 (LMC) 24.9 (LMC) 25.1 (LMC) MMC Perfect Form Boundary 25 (MMC) 24.9 (LMC) 25 (MMC) 25.1 (LMC) 24.9 (LMC)

Virtual and Resultant Condition Boundaries

Internal and External Features (MMC Concept)

Virtual Condition Boundary

Internal Feature (MMC Concept) 14 +/- 0.5

A C XX.X

XX.X

B ( Virtual Condition Inner Boundary Maximum Inscribed ) Diameter Boundary of MMC Hole Shown at Extreme Limit

As Shown on Drawing

1 Positional Tolerance Zone at MMC True (Basic) Position of Hole True (Basic) Position of Hole Other Possible Extreme Locations Axis Location of MMC Hole Shown at Extreme Limit Calculating Virtual Condition 13.5 MMC Size of Feature 1 Applicable Geometric Tolerance 12.5 Virtual Condition Boundary

Resultant Condition Boundary

Internal Feature (MMC Concept) 14 +/- 0.5

A C XX.X

XX.X

As Shown on Drawing

( Resultant Condition Outer Boundary Minimum Circumscribed Diameter ) Boundary of LMC Hole Shown at Extreme Limit True (Basic) Position of Hole

Calculating Resultant Condition

(Internal Feature) 14.5 LMC Size of Feature 2 Geometric Tolerance (at LMC) 16.5 Resultant Condition Boundary 2 Positional Tolerance Zone at LMC True (Basic) Position of Hole Other Possible Extreme Locations Axis Location of LMC Hole Shown at Extreme Limit

Virtual Condition Boundary

External Feature (MMC Concept) 14 +/- 0.5

A C XX.XX

XX.X

B ( Virtual Condition Outer Boundary Minimum Circumscribed Diameter ) Boundary of MMC Feature Shown at Extreme Limit

As Shown on Drawing

1 Positional Tolerance Zone at MMC True (Basic) Position of Feature True (Basic) Position of Feature Other Possible Extreme Locations Axis Location of MMC Feature Shown at Extreme Limit Calculating Virtual Condition 14.5 MMC Size of Feature 1 Applicable Geometric Tolerance 15.5 Virtual Condition Boundary

Resultant Condition Boundary

External Feature (MMC Concept) 14 +/- 0.5

A C XX.X

XX.X

B ( Resultant Condition Inner Boundary Maximum Inscribed ) Diameter

As Shown on Drawing

2 Positional Tolerance Zone at LMC Boundary of LMC feature Shown at Extreme Limit True (Basic) Position of Feature True (Basic) Position of Feature Other Possible Extreme Locations Axis Location of LMC Feature Shown at Extreme Limit

Calculating Resultant Condition

(External Feature) 13.5 LMC Size of Feature 2 Geometric Tolerance (at LMC) 11.5 Resultant Condition Boundary

• 3X 5.0  5mm is 3 times repeated. A space is used after X

Maximum Material Condition (MMC):

The condition where the feature contains the maximum material within the stated limits of size – for example, the largest pin or the smallest hole.

Least Material Condition (LMC):

The condition where the feature contains the least material with in the stated limits of size - for example, the smallest pin or largest hole.

GEOMETRIC CHARACTERISTIC SYMBOLS TYPE OF TOLERANCE CHARACTERISTIC

FOR INDIVIDUAL FEATURES FORM STRAIGHNESS FLATNESS FOR INDIVIDUAL OR RELATED FEATURES FROFILE PROFILE OF A SURFACE PROFILE OF A LINE ANGULARITY ORIENTATION PERPENDICULARITY PARALLELISM FOR RELATED FEATURES POSITION CONCENTRICITY LOCATION SYMMETRY RUNOUT CIRCULARITY (ROUNDNESS) CYLINDRICITY CIRCULAR RUNOUT TOTAL RUNOUT

SYMBOL