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

Tolerances of Form(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 Tolerance 25.1 (LMC) MMC Perfect Form BoundaryInternal Feature of Size

Extreme Variations of Form Allowed By Size Tolerance MMC Perfect Form BoundaryExternal Feature of Size

25 +/-0.250.1 Tolerance0.5 ToleranceStraightness is the condition where an element of a surface or an axis is a straight lineStraightness (Flat Surfaces)

Straightness (Flat Surfaces)24.75 min25.25 max0.5 Tolerance ZoneThe straightness tolerance is applied in the view where the elements to be controlled are represented by a straight lineIn 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)MMC0.1 Tolerance ZoneMMC0.1 Tolerance ZoneMMC0.1 Tolerance ZoneIn 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)0.1Outer Boundary (Max)MMC0.1 Diameter Tolerance ZoneOuter Boundary = Actual Feature Size + Straightness ToleranceIn this example the derived median line of the features 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 14.8515.1 Virtual Condition 15 (MMC)0.1 Diameter Tolerance Zone15.1 Virtual Condition14.85 (LMC)0.25 Diameter Tolerance ZoneVirtual Condition = MMC Feature Size + Straightness ToleranceIn this example the derived median line of the features 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.

FlatnessFlatness 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 +/-0.2524.75 min25.25 max0.10.1 Tolerance Zone0.1 Tolerance ZoneIn 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 tolerance900.1 Wide Tolerance ZoneCircularity (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.

CylindricityCylindricity 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 ZoneMMCIn 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 circularelement (2-D) controls.Form Control QuizThe 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 features size.A features form tolerance must be less than its sizetolerance.Flatness controls the orientation of a feature.Size limits implicitly control a features form.6.7.8.9.10.Questions #1-5 Fill in blanks (choose from below)straightnessflatnesscircularitycylindricityperfect formstraighttaperedprofiletrue positionangularityAnswer questions #6-10 True or False

Tolerances of OrientationPerpendicularity(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.20 +/-0.519.5 min0.3 Wide Tolerance Zone20.5 max0.3 Wide Tolerance ZoneThe 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 feature axis at a specified angle (other than 90 degrees) to the datum reference plane, within the specified tolerance zone.0.3A60oThe 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 ZoneNOTE: Tolerance applies to feature at RFSAngularity 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 ZoneDatum 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 cylinder

0.3 Wide Tolerance ZonePerpendicularity 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)The tolerance zone in this example is defined by two parallel planes 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 Surface)0.3 Circular Tolerance Zone0.3 Diameter Tolerance Zone0.3 Circular Tolerance ZoneNOTE: Tolerance applies to feature at RFSThe 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 RFSThe 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

25 +/-0.525.5 max0.3 Wide Tolerance Zone24.5 min0.3 Wide Tolerance ZoneParallelism 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.

0.3 Wide Tolerance Zone Parallelism (Feature Axis to Datum Surface)NOTE: The specified tolerance does not apply to the orientation of the feature axis in this directionParallelism 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

Parallelism (Feature Axis to Datum Surfaces)0.3 Circular Tolerance Zone0.3 Circular Tolerance Zone0.3 Circular Tolerance ZoneParallelism 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

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.0.1 Circular Tolerance Zone0.1 Circular Tolerance ZoneDatum Axis AThe 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 QuizThe three orientation controls are __________, ___________, and ________________. 1.2.3.4.5.A _______________ is always required when applying any ofthe orientation controls.________________ is the appropriate geometric tolerance whencontrolling the orientation of a feature at right angles to a datumreference.Orientation tolerances indirectly control a features form.Mathematically all three orientation tolerances are _________.Orientation tolerances do not control the ________ of a feature.6.Orientation tolerance zones can be cylindrical.Parallelism tolerances do not apply to features of size.To apply an angularity tolerance the desired angle 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)angularityperpendicularityparallelismdatum referenceidenticallocationprofiledatum featuredatum targetAnswer questions #6-10 True or False

Tolerances of RunoutTotal Runout(ASME Y14.5M-1994 ,6.7.1.2.2)

Datum featureDatum axis (established from datum featureAngled surfaces constructed around a datum axisExternal surfaces constructed around a datum axisInternal surfaces constructed around a datum axisSurfaces constructed perpendicular to a datum axis Features Applicable to Runout Tolerancing

0+- Full Indicator MovementMaximumMinimumTotal ToleranceMaximum ReadingMinimum ReadingFull Part RotationMeasuring position #1 (circular element #1)Circular RunoutWhen 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.

As Shownon DrawingMeans This:Datum axis ASingle circular elementCircular Runout (Angled Surface to Datum Axis)50 +/-0.25NOTE: 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 surfaceThe 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 Drawing50 +/-0.25Circular Runout (Surface Perpendicular to Datum Axis)Datum axis ASingle circular elementNOTE: 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 surfaceThe 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.

Allowable indicator reading = 0.75 max.Single circular elementMeans This:As Shownon Drawing50 +/-0.25Datum axis AWhen 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

Allowable indicator reading = 0.75 max.Single circular elementMeans This:As Shownon DrawingDatum axis A-BWhen 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 surfaceMachine centerMachine center

As Shownon Drawing50 +/-0.25Circular Runout (Surface Related to Datum Surface and Axis)Datum axis BSingle circular elementThe 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:Allowable indicator reading = 0.75 max.When measuring circular runout, the indicator must be reset when repositioned along the feature surface.Collet or ChuckStop collarDatum plane A

0+Full Indicator MovementTotal ToleranceMaximum ReadingMinimum ReadingFull Part Rotation- Total RunoutMaximumMinimumWhen 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 PathTotal runout can only be applied on an RFS basis and cannot be modified to MMC or LMC.

Full Part RotationAs Shownon Drawing50 +/-0.250.75AMeans This:Datum axis AThe 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.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 surfaceTotal Runout (Angled Surface to Datum Axis)Collet or ChuckWhen 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.

Total Runout (Surface Perpendicular to Datum Axis)As Shownon Drawing50 +/-0.25Datum axis AFull Part Rotation3510Means 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 QuizAnswer questions #1-12 True or FalseTotal 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 features size.11.Total runout can control circularity, straightness, taper,coaxiality, angularity and any other surface variation.12.

Tolerances of ProfileProfile of a LineProfile of a Surface(ASME Y14.5M-1994, 6.5.2b)(ASME Y14.5M-1994, 6.5.2a)

18 MaxProfile of a Line 2 Wide Size Tolerance ZoneA17 +/- 11 Wide Profile Tolerance Zone 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 OrientationA 2 A B C23.523.5Nominal LocationThe 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 C 50C501 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 CNominal Location0.5 Inboard0.5 OutboardProfile 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 C50C500.5 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 CNominal Location

Profile of a Surface A120 X 20A320 X 20C501.2 A B CBC500.5 Inboard0.7 Outboard1.2 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).0.5Nominal Location

25A0.50.125.2524.750.1 Wide Tolerance Zone Composite Profile of Two Coplanar Surfaces w/o Orientation RefinementProfile of a Surface Form OnlyLocation & Orientation

0.1 Wide Tolerance Zone0.1 Wide Tolerance Zone25.2524.7525A0.5A0.1Form & Orientation Composite Profile of Two Coplanar Surfaces With Orientation RefinementProfile of a Surface Location

6.Profile Control QuizProfile tolerances always require a datum reference.Answer questions #1-13 True or False1.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 QuizThe 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 referencecomposite profilebilaterallocationformprimary datumtrue geometric counterpartorientationprofile of a surfaceunilateralvirtual condition

Tolerances of LocationTrue PositionConcentricitySymmetry(ASME Y14.5M-1994, 5.2)(ASME Y14.5M-1994, 5.12)(ASME Y14.5M-1994, 5.13)

Notes

10.25 +/- 0.510.25 +/- 0.5RectangularTolerance Zone10.2510.25Circular Tolerance ZoneBCoordinate vs GeometricTolerancing MethodsCoordinate DimensioningGeometric DimensioningRectangular Tolerance ZoneCircular Tolerance Zone57% LargerTolerance ZoneIncreased Effective Tolerance

Formula to determine the actual radial position of a feature using measured coordinate values (RFS)XYZ Feature axis actual location (measured)Positional tolerance zone cylinderFeature axis true position (designed)Positional Tolerance VerificationZ =total radial deviationX measured deviationY measured deviationActual 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 Z =XYZ Feature axis actual location (measured)Positional tolerance zone cylinderFeature axis true position (designed)Positional Tolerance VerificationZ =total radial deviationX measured deviationY measured deviationActual feature boundary2= positional tolerance(Applies when a circular tolerance is indicated)

Bi-directional True PositionRectangular Coordinate MethodAB0.5 A B C2X2X1.5 WideTolerance Zone0.5 WideTolerance ZoneTrue Position Relatedto Datum Reference FrameEach axis must lie within the 1.5 X 0.5 rectangular tolerance zone basically located to the datum reference frameAs Shownon DrawingMeans This:

Bi-directional True PositionMultiple Single-Segment Method1.5 WideTolerance Zone0.5 WideTolerance ZoneTrue Position Relatedto Datum Reference FrameEach axis must lie within the 1.5 X 0.5 rectangular tolerance zone basically located to the datum reference frameAs Shownon DrawingMeans This:

As Shownon DrawingMeans This:1.5 A B C0.5 A B CBOUNDARYBOUNDARY1035102X 13 +/-0.252X 6 +/-0.25Both 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. Theboundary concept can only be applied on anMMC basis.True position boundary relatedto datum reference frameBi-directional True PositionNoncylndrical Features (Boundary Concept)

Composite True PositionWithout Pattern Orientation ControlTrue Position Relatedto Datum ReferenceFrameBEach axis must lie within each tolerance zone simultaneouslyAs Shownon DrawingMeans This:2X 6 +/-0.251.5 A B C0.5 Apattern location relative to Datums A, B, and Cpattern orientation relative to Datum A only (perpendicularity)

Composite True PositionWith Pattern Orientation ControlTrue Position Relatedto Datum ReferenceFrameEach axis must lie within each tolerance zone simultaneouslyAs Shownon DrawingMeans This:2X 6 +/-0.25pattern location relative to Datums A, B, and Cpattern orientation relative to Datums A and B1.5 A B C0.5 A B

Location (Concentricity)Datum Features at RFS15.9515.90As Shown on DrawingDerived Median Points of Diametrically Opposed ElementsAxis of DatumFeature 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 A6.35 +/- 0.05 0.5 Coaxial Tolerance Zone

Location (Symmetry)Datum Features at RFS15.9515.900.5 A6.35 +/- 0.05Derived MedianPointsCenter Plane of Datum Feature A0.5 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 QuizAnswer questions #1-11 True or FalsePositional 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 features size.Positional tolerances are applied on an MMC, LMC, orRFS basis.2.3.4.5.True position tolerance values are used to calculate the minimum size of a feature required for assembly.6.Composite true position tolerances should be avoidedbecause it is overly restrictive and difficult to check.Composite true position tolerances can only be 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 circularity9.10.11.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 spherical1.2.3.4.5.________________ 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 determineappropriate clearance hole sizes for mating details6.7._________ tolerance zones are recommended to prevent fastener interference in mating details.8.projected3-dimensionalsurface boundaryfloatinglocationfixedbasic dimensionsmaximum materialcylindricalpattern-locatingrectangularfeature-relatingTrue Position QuizQuestions #1-9 Fill in blanks (choose from below)The tolerance shown in the upper segment of a composite trueposition feature control frame is called the ________________ tolerance zone.The tolerance shown in the lower segment of a composite trueposition feature control frame is called the ________________ tolerance zone.9.Functional gaging principles can be applied when __________________ condition is specifiedaxis

Notes

Notes

Fixed andFloatingFastenerExercises

ACalculate Required Positional ToleranceCalculate Nominal SizeT = H - FH = Minimum Hole Size = 10.25 F = Max. Fastener Size = 10 T = 10.25 -10 T = ______Floating FastenersH = F +TF = Max. Fastener Size = 10T = Positional Tolerance = 0.50H = 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 toleranceremember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

0.252x10.50+/- 0.25M0.52x10.75+/- 0.25Floating FastenersREMEMBER!!! All Calculations Apply at MMCT = H - F H = Minimum Hole Size = 10.25 F = Max. Fastener Size = 10T = 10.25 -10T = 0.25Calculate Required Positional ToleranceF = Max. Fastener Size = 10T = Positional Tolerance = 0.5H = 10 + .5 H = 10.5 MinimumH = F +TIn 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 toleranceremember: 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 = 0.800.82x??.??+/- 0.25Calculate Required Clearance Hole Size. 2X M10 X 1.5Fixed FastenersH = 10.00 + 2(0.8) H = _____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.)APPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED Nominal Size (MMC For Calculations)H = F + 2Tremember: the size tolerance must be added to the calculated MMC size to obtain the correct nominal value.

2x11.85+/- 0.25Calculate Required Clearance Hole Size. 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 FastenersH = F + 2TF = Max. Fastener Size = 10.00 T = Positional Tolerance = 0.80H = 10.00 + 2(0.8) H = 11.60 MinimumAPPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED2X M10 X 1.5 Nominal 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

2x11.85+/- 0.25Calculate Required Clearance Hole Size. 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 FastenersH = F + 2TF = Max. Fastener Size = 10T = Positional Tolerance = 0.8H = 10 + 2(0.8) H = 11.6 MinimumAPPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED2X M10 X 1.5 Nominal 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

0.52x11.25+/- 0.25MIn 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 FastenersT = (H - F)/2H = Minimum Hole Size = 11F = Max. Fastener Size = 10T = (11 - 10)/2 T = 0.502X M10 X 1.50.5M10PAPPLIES WHEN A PROJECTED TOLERANCE ZONE IS USED Nominal Size (MMC For Calculations)REMEMBER!!! All Calculations Apply at MMC

0.52x??.??+/- 0.25Calculate Required Clearance Hole Size. Fixed FastenersF = Max. Fastener Size = 10T1 = Positional Tol. (A) = 0.50 T2 = Positional Tol. (B) = 1H = 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 USED2X M10 X 1.5 Nominal Size (MMC For Calculations)remember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

0.52x11.75+/- 0.25Calculate Required Clearance Hole Size. 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 FastenersF = Max. Fastener Size = 10T1 = Positional Tol. (A) = 0.5 T2 = Positional Tol. (B) = 1H = 10 + (0.5 + 1) H = 11.5 MinimumAPPLIES WHEN A PROJECTED TOLERANCE ZONE IS USEDH=F+(T1 + T2)2X M10 X 1.5 Nominal 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

DPHFAPPLIES WHEN A PROJECTED TOLERANCE ZONE IS NOT USEDCalculate Nominal Size0.5MIn 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 FastenersH = 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 pinF = Max. pin size = 10T1 = Positional Tol. (A) = 0.5T2 = Positional Tol. (B) = 0.5 D = Min. pin depth = 20. P = Max. pin projection = 15

DPHFH= 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 pinAPPLIES WHEN A PROJECTED TOLERANCE ZONE IS NOT USED2x 12 +/-0.25Calculate Nominal SizeF = Max. pin size = 10T1 = Positional tol. (A) = 0.5T2 = Positional tol. (B) = 0.5 D = Min. pin depth = 20 P = Max. pin projection = 15H= F + T1 + T2 (1+(2P/D))H = 10 + 0.5 + 0.5(1 + 2(15/20)) H = 11.75 MinimumIn 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 FastenersH= F + T1 + T2 (1+(2P/D))REMEMBER!!! All Calculations Apply at MMCremember: the size tolerance must be added to the calculated MMC hole size to obtain the correct nominal value.

Answers to Quizzesand Exercises

Rules and Definitions Quiz1. 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.FALSETRUEFALSETRUETRUEFALSEFALSETRUETRUETRUEFALSEFALSEQuestions #1-12 True or False

Material Condition QuizInternal Features MMC LMCExternal Features MMC LMC23.45 +0.05/-0.2523.45 +0.05/-0.2510.75 +0/-0.25Calculate appropriate valuesFill in blanks10.75 1123.2 23.5123.4 123.6.890 .89510.75 10.523.5 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 Quiz11. All tooling locators (CDs) are used as datums.Questions #1-12 True or False7. Datums are actual part features.FALSEFALSEFALSEFALSETRUETRUEFALSETRUETRUETRUEFALSETRUE

Datum QuizThe 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-rotational degrees 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)primarysecondarytertiary3-rotational3-linear2-rotationaldatumthreetwoonesixfunctionalrestrain movementcoordinateddatum simulatordatum featurerepeatablefive1-linear

Straightness and circularity are individual line or circularelement (2-D) controls.Form Control QuizThe 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 features size.A features form tolerance must be less than its sizetolerance.Flatness controls the orientation of a feature.Size limits implicitly control a features form.6.7.8.9.10.FALSETRUETRUETRUEFALSEAnswer questions #6-10 True or FalseQuestions #1-5 Fill in blanks (choose from below)straightnessflatnesscircularitycylindricityperfect formstraighttaperedprofiletrue positionangularity

Orientation Control QuizThe three orientation controls are angularity, parallelism, and perpendicularity. 1.2.3.4.5.A datum reference is always required when applying any ofthe orientation controls.Perpendicularity is the appropriate geometric tolerance whencontrolling the orientation of a feature at right angles to a datumreference.Orientation tolerances indirectly control a features form.Mathematically all three orientation tolerances are identical.Orientation tolerances do not control the location of a feature.Answer questions #6-10 True or False6.TRUEOrientation 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.TRUEFALSEFALSETRUETo apply a perpendicularity tolerance the desired anglemust be indicated as a basic dimension.Questions #1-5 Fill in blanks (choose from below)angularityperpendicularityparallelismdatum referenceidenticallocationprofiledatum featuredatum target

Runout Control QuizAnswer questions #1-12 True or FalseTRUETotal 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.FALSECircular runout tolerances apply to single elements .FALSETRUETRUE6.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.TRUECircular runout can be applied to control taper of a part.9.FALSETotal runout tolerances are an appropriate way to limit wobble of a rotating surface.10.Runout tolerances are used to control a features size.11.Total runout can control circularity, straightness, taper,coaxiality, angularity and any other surface variation.12.TRUEFALSETRUETRUEFALSE

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 QuizThe two types of profile tolerances are profile of a line, andprofile 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 referencecomposite profilebilaterallocationformprimary datumtrue geometric counterpartorientationprofile of a surfaceunilateralvirtual condition

6.Profile Control QuizProfile tolerances always require a datum reference.Answer questions #1-13 True or False1.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.TRUEFALSEFALSEFALSETRUETRUETRUEFALSEFALSEFALSETRUETRUEFALSE

True Position QuizAnswer questions #1-11 True or FalseTRUEPositional 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 features size.Positional tolerances are applied on an MMC, LMC, orRFS basis.2.3.4.5.FALSETrue position tolerance values are used to calculate the minimum size of a feature required for assembly.TRUETRUE6.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.TRUEPositional tolerances can be used to control circularity9.FALSE10.11.TRUEFALSETRUEFALSETRUEThe 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 rectangular, cylindrical,or spherical1.2.3.4.5.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 determineappropriate clearance hole sizes for mating details6.7.Projected tolerance zones are recommended to prevent fastener interference in mating details.8.projected3-dimensionalsurface boundaryfloatinglocationfixedbasic dimensionsmaximum materialcylindricalpattern-locatingrectangularfeature-relatingTrue Position QuizQuestions #1-9 Fill in blanks (choose from below)The tolerance shown in the upper segment of a composite trueposition feature control frame is called the pattern-locating tolerance zone.The tolerance shown in the lower segment of a composite trueposition feature control frame is called the feature-relating tolerance zone.9.Functional gaging principles can be applied when maximummaterial condition is specifiedaxis

END

Notes

Notes

Notes

Extreme Variations of Form Allowed By Size Tolerance 25.1 (LMC) MMC Perfect Form Boundary 25 (MMC)

Virtual andResultantConditionBoundaries

Internal and ExternalFeatures (MMC Concept)

Virtual Condition BoundaryInternal Feature (MMC Concept)AAs Shown on DrawingAxis Location of MMC Hole Shown at Extreme LimitBoundary of MMC HoleShown at Extreme LimitTrue (Basic)Position of HoleTrue (Basic)Position of HoleOther PossibleExtreme Locations

Resultant Condition BoundaryInternal Feature (MMC Concept)B16.5 Resultant Condition Boundary14.5 LMC Size of Feature2 Geometric Tolerance (at LMC)Calculating Resultant Condition (Internal Feature)As Shown on DrawingAxis Location of LMC Hole Shown at Extreme LimitBoundary of LMC HoleShown at Extreme Limit 2 Positional Tolerance Zone at LMCTrue (Basic)Position of HoleTrue (Basic)Position of HoleOther PossibleExtreme Locations

Virtual Condition BoundaryExternal Feature (MMC Concept)15.5 Virtual Condition Boundary14.5 MMC Size of Feature1 Applicable Geometric ToleranceCalculating Virtual Condition14 +/- 0.5As Shown on DrawingAxis Location of MMC Feature Shown at Extreme LimitBoundary of MMC FeatureShown at Extreme LimitTrue (Basic)Position of FeatureTrue (Basic)Position of FeatureOther PossibleExtreme LocationsVirtual ConditionOuter BoundaryMinimum CircumscribedDiameter()

Resultant Condition BoundaryExternal Feature (MMC Concept)1 A B C14 +/- 0.5CBA11.5 Resultant Condition Boundary13.5 LMC Size of Feature2 Geometric Tolerance (at LMC)Calculating Resultant Condition (External Feature)As Shown on DrawingAxis Location of LMC Feature Shown at Extreme LimitBoundary of LMC featureShown at Extreme LimitTrue (Basic)Position of FeatureTrue (Basic)Position of FeatureOther PossibleExtreme Locations