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GD&T Trainer: Fundamentals 1994

Based on ASME Y14.5M-1994 

Goals and Objectives

Lesson 1: Dimensions and Drawings
Goal: Understand what dimensioning and tolerancing is.

  • Describe what a dimension is.
  • Describe what a tolerance is.
  • Describe what a limit tolerance is.
  • Describe what a plus-minus tolerance is.
  • Identify the nominal of a dimension.
  • Explain how dimensional limits are interpreted.
  • Explain what the geometric dimensioning and tolerancing system is.
  • Explain "ASME Y14.5M-1994."
  • Identify the three major benefits of geometric dimensioning and tolerancing.

Lesson 2: Key Terms
Goal: Understand seven key terms used in geometric tolerancing.

  • Define a feature.
  • Define a feature of size.
  • Define actual local size.
  • Define actual mating envelope.
  • Describe the maximum material condition of a feature of size.
  • Describe the least material condition of a feature of size.
  • Describe the term "regardless of feature size."

Lesson 3: Modifiers and Symbols
Goal: Understand the modifiers and symbols used in geometric tolerancing.

  • Name the fourteen geometric characteristic symbols.
  • Identify the five types of geometric characteristic symbols.
  • Identify the six common modifying symbols used in geometric tolerancing.
  • Identify the parts of a feature control frame.
  • Identify the ten additional symbols used in geometric tolerancing.

Lesson 4: GD&T Rules
Goal: Understand Rule #1 and Rule #2.

  • Explain Rule #1.
  • Recognize the three components of the envelope principle.
  • Determine when Rule #1 applies to a dimension.
  • Describe the Rule #1 envelope boundary.
  • Describe a limitation of Rule #1.
  • List two ways Rule #1 can be overridden.
  • Explain Rule #2 and Rule #2a.

Lesson 5: GD&T Concepts
Goal: Understand the concepts of basic dimensions, worst-case boundary, virtual condition, inner and outer boundary, and bonus tolerance.

  • Describe a basic dimension.
  • List two uses for basic dimensions.
  • Explain the term "worst-case boundary."
  • Explain the concept of virtual condition.
  • Calculate the virtual condition of a feature of size.
  • Explain the concepts of inner boundary and outer boundary.
  • Explain the concept of bonus tolerance.
  • Calculate the amount of bonus tolerance permissible.

Lesson 6: Flatness
Goal: Interpret the flatness control.

  • Describe what flatness is.
  • Describe the tolerance zone for a flatness control.
  • Describe which modifiers can be used in a flatness control.
  • Identify the three requirements in a flatness application.
  • Describe how Rule #1 provides an indirect flatness control.
  • Describe two common applications for a flatness control.
  • Describe how a flatness control can be inspected.

Lesson 7: Straightness
Goal: Interpret the straightness control.

  • Describe the difference between derived median line and axis.
  • Describe the difference between derived median plane and centerplane.
  • Describe what straightness is.
  • Describe the tolerance zone for straightness applied to a surface.
  • Describe which modifiers can be used with a straightness control applied to a surface.
  • Determine if a straightness control is applied to a surface or feature of size.
  • Describe the tolerance zone for a straightness control applied to a feature of size.
  • Describe how Rule #1 provides an indirect straightness control.
  • Recognize when a straightness control overrides Rule #1.
  • Describe which modifiers can be used with a straightness control applied to a feature of size.
  • Calculate the amount of bonus in a straightness MMC application.
  • Describe two common applications of a straightness control.
  • Describe how a straightness control can be inspected.

Lesson 8: Circularity
Goal: Interpret the circularity control.

  • Describe what circularity is.
  • Describe the tolerance zone for a circularity control.
  • Describe which modifiers can be used in a circularity control.
  • Describe how Rule #1 provides an indirect circularity control.
  • List three conditions of a circularity application.
  • Describe two common applications of a circularity control.
  • Describe how a circularity control can be inspected.

Lesson 9: Cylindricity
Goal: Interpret the cylindricity control.

  • Describe what cylindricity is.
  • Describe three requirements of a cylindricity control.
  • Describe the tolerance zone for a cylindricity control.
  • Describe which modifiers can be used in a cylindricity control.
  • Describe how Rule #1 provides an indirect cylindricity control.
  • List three conditions of a cylindricity application.
  • Describe a common application of a cylindricity control.
  • Describe how a cylindricity control can be inspected.

Lesson 10: Planar Datums
Goal: Understand the datum system (planar datums).

  • Describe the datum system.
  • List three benefits of the datum system.
  • Define an implied datum.
  • Define a datum.
  • Define a datum feature.
  • Define a true geometric counterpart.
  • Define a datum feature simulator.
  • Define the datum feature symbol.
  • Describe four ways to specify a planar datum.
  • Describe how to reference datums in a feature control frame.
  • Describe a datum reference frame.
  • List six degrees of part freedom in space.
  • Describe coplanar datum features.

Lesson 11: Datum Targets
Goal: Interpret datum targets.

  • Describe datum targets.
  • List three situations where datums targets should be used.
  • Recognize the datum target symbol.
  • State when a datum target specification is on the front or back surface in a view on a drawing.
  • Describe why basic dimensions are used to locate datum targets.
  • Draw a simulated gage for a datum target point specification.
  • Draw a simulated gage for a datum target line specification.
  • Draw a simulated gage for a datum target area specification.


Lesson 12: Size Datums (RFS)
Goal: Interpret feature of size datum specifications at RFS.

  • Describe the datum that results from a feature of size datum feature.
  • List three ways to specify an axis as a datum
  • List three ways to specify a centerplane as a datum.
  • Explain how feature of size datum references communicate size condition.
  • Draw the datum feature simulator for an external feature of size datum axis (RFS primary).
  • Draw the datum feature simulator for an internal feature of size datum axis (RFS primary).
  • Draw the datum feature simulator for an internal feature of size datum centerplane (RFS primary).
  • Draw the datum feature simulator for an external feature of size datum centerplane (RF primary).
  • Describe coaxial datum features.

Lesson 13: Size Datums (MMC)
Goal: Interpret feature of size datum specifications at MMC.

  • List three conditions when referencing a feature of size datum feature at MMC.
  • Draw the datum feature simulator for an external feature of size datum axis (MMC primary).
  • Draw the datum feature simulator for an internal feature of size datum axis (MMC primary).
  • Explain the concept of datum shift.
  • Recognize when datum shift is permissible.
  • Calculate the amount of datum shift permissible.

Lesson 14: Orientation Controls
Goal: Understand the basics of orientation controls.

  • Describe when to use each orientation control.
  • Describe what controls the tolerance on implied 90° angles.
  • Describe how parallelism is controlled when no symbol is shown.
  • Explain the definition of perpendicularity.
  • Explain the definition of angularity.
  • Explain the definition of parallelism.
  • Describe the common tolerance zones for orientation controls.
  • List two requirements for orientation controls.
  • List two indirect orientation controls.

Lesson 15: Perpendicularity
Goal: Interpret the perpendicularity control.

  • List two common tolerance zones for a perpendicularity control.
  • List two requirements of a perpendicularity control.
  • Describe the tolerance zone for a perpendicularity control applied to a surface.
  • Explain how a perpendicularity control applied to a surface affects its flatness.
  • Explain the effect of applying a perpendicularity control to a feature of size.
  • Explain how to specify a cylindrical tolerance zone for a perpendicularity control.
  • Explain the tolerance zone when a perpendicularity control is applied to a cylindrical feature of size.
  • Explain the effects of a MMC modifier in a perpendicularity control.
  • Describe the gage for an application using a perpendicularity control applied at MMC.
  • Describe two common applications for a perpendicularity control.

Lesson 16: Angularity
Goal: Interpret the angularity control.

  • List two common tolerance zones for an angularity control.
  • List two requirements of an angularity control.
  • Describe the tolerance zone for an angularity control applied to a surface.
  • Explain how an angularity control applied to a surface affects its flatness.
  • Explain the effect of applying an angularity control to a feature of size.
  • Explain how to specify a cylindrical tolerance zone for an angularity control.
  • Explain the tolerance zone when an angularity control is applied to a cylindrical feature of size.
  • Describe two applications for angularity.
  • Explain how an angularity control can be inspected.

Lesson 17: Parallelism
Goal: Interpret the parallelism control.

  • List two common tolerance zones for a parallelism control.
  • List two requirements of a parallelism control.
  • Describe the tolerance zone for a parallelism control applied to a surface.
  • Explain how a parallelism control applied to a surface affects its flatness.
  • Explain the effect of applying a parallelism control to a feature of size.
  • Describe how to specify a cylindrical tolerance zone for a parallelism control.
  • Interpret the effects of specifying the tangent plane modifier with a parallelism control.
  • Describe two applications for parallelism.
  • Explain how a parallelism control can be inspected.

Lesson 18: Position - Introduction
Goal: Understand the fundamental concepts of tolerance of position: the definitions and conventions, the advantages, and the basic theories.

  • Define the term "tolerance of position."
  • Define a tolerance of position control.
  • Describe one requirement of a tolerance of position control.
  • List two types of implied basic relationships common with tolerance of position.
  • List six advantages of tolerance of position.
  • List four types of relationships that can be controlled with tolerance of position.
  • Describe when the MMC modifier should be specified in a tolerance of position control.
  • Explain the virtual condition boundary theory for tolerance of position.
  • Explain the axis theory for tolerance of position.

Lesson 19: Position - RFS/MMC/LMC
Goal: Interpret RFS, MMC and LMC tolerance of position applications.

  • List three conditions that apply when a tolerance of position control is applied at RFS.
  • Describe two common tolerance zone shapes for a tolerance of position control at RFS.
  • Calculate the worst-case boundary for a feature of size controlled with tolerance of position at RFS.
  • List three conditions that exist when an MMC modifier is used in a tolerance of position application.
  • Describe the tolerance zone in tolerance of position MMC applications.
  • Calculate the virtual condition of a feature of size controlled with a tolerance of position at MMC.
  • Calculate the amount of bonus tolerance permissible for a tolerance of position application.
  • Calculate the amount of datum shift available in a coaxial diameter tolerance of position application.
  • Describe when a tolerance of position control should use the LMC modifier.
  • Describe how bonus tolerance is calculated in an LMC position application.
  • Describe four common applications for a tolerance of position control.
  • Describe how a tolerance of position control applied at RFS can be inspected.
  • Define the term "cartoon gage."
  • Describe how a tolerance of position control applied at MMC can be inspected.


Lesson 20: Position - Special Applications
Goal: Interpret tolerance of position special applications.

  • Describe the tolerance zone(s) in a tolerance of position application of an elongated hole.
  • Describe when to use the projected tolerance zone modifier.
  • Describe the tolerance zone(s) in a tolerance of position application with the projected tolerance zone modifier.
  • Recognize when a tolerance of position control is used to control a symmetrical relationship.
  • Describe the tolerance zone(s) in a tolerance of position application used to control the spacing and orientation of a hold pattern.
  • Describe when a multiple single-segment tolerance of position control should be specified.
  • Interpret a multiple single-segment tolerance of position control.
  • Describe what a composite tolerance of position control is.
  • Describe when a composite tolerance of position control should be specified.
  • Interpret a composite tolerance of position control application.
  • Recognize two major differences between multiple single-segment and composite position controls.


Lesson 21: Fastener Formulas
Goal: Calculate tolerance of position tolerance values using the fixed and floating fastener formulas.

  • Describe a fixed fastener formula.
  • Write the fixed fastener formula.
  • Calculate tolerance of position tolerance values for fixed fastener applications.
  • Describe a floating fastener formula.
  • Write the floating fastener formula.
  • Calculate tolerance of position tolerance values for floating fastener applications.
  • List two limitations of using the fastener formulas.


Lesson 22: Concentricity
Goal: Interpret the concentricity control.

  • Describe a median point.
  • Describe the term "concentricity."
  • Describe the tolerance zone for a concentricity control.
  • List three requirements of a concentricity control.
  • Interpret a concentricity control application.
  • Describe one difference between concentricity and tolerance of position (RFS).
  • Describe one common application for concentricity.
  • Describe how a concentricity control can be inspected.

Lesson 23: Symmetry
Goal: Interpret the symmetry control.

  • Describe the term "symmetry."
  • Describe the tolerance zone for a symmetry control.
  • Interpret a symmetry control application.
  • Describe one difference between symmetry and tolerance of position (RFS).
  • Describe one common application for symmetry.
  • Describe how a symmetry control can be inspected.

Lesson 24: Circular Runout
Goal: Interpret the circular runout control.

  • Describe what runout is.
  • List two types of runout controls.
  • List three ways a datum axis can be specified for a runout control.
  • Explain what circular runout is.
  • Describe the tolerance zone for a circular runout control (applied to a diameter).
  • Describe how circular runout can be inspected.
  • Describe how circular runout is a composite control.
  • Determine the maximum amount of axis offset from a circular runout control.
  • Interpret a circular runout application.
  • Describe two common applications for circular runout.

Lesson 25: Total Runout
Goal: Interpret the total runout control.

  • Describe what total runout is.
  • List two requirements of a total runout control.
  • Describe the tolerance zone for a total runout control (applied to a diameter).
  • Describe how total runout is verified.
  • Describe how total runout is a composite control.
  • Determine the maximum amount of axis offset from a total runout control.
  • Describe two similarities between circular and total runout.
  • Describe two differences between circular and total runout.
  • Describe two common applications for total runout.

Lesson 26: Introduction to Profile
Goal: Understand profile tolerancing.

  • Describe how profile can be a related feature control or a form control.
  • Describe the term "profile."
  • Describe the term "true profile."
  • Describe the term "profile control."
  • Describe the four characteristics that profile can control.
  • Describe the difference in tolerance zones for a profile of a surface and a profile of a line control.
  • Recognize the four types of profile tolerance zone specifications.
  • Describe a bilateral tolerance zone for a profile control.
  • Describe a unilateral tolerance zone for a profile control.
  • Recognize the symbol for "between."
  • Recognize the symbol for "all around."
  • Describe the extent to which a profile control tolerance zone applies on a part.
  • List three advantages of using profile controls.

Lesson 27: Profile of a Surface
Goal: Interpret the profile of a surface control.

  • List four part characteristics profile of a surface can be used to control.
  • List two requirements of profile of a surface applied to a surface.
  • Describe the part characteristics being controlled when a profile of a surface is used to control a surface location.
  • List two requirements of a profile of a surface control applied to a polygon.
  • Describe the part characteristics being controlled when profile of a surface is applied to a polygon.
  • List two requirements of a profile of a surface control applied to a cone.
  • Describe the part characteristics being controlled when profile of a surface is applied to a conical feature.
  • List two requirements of profile of a surface applied to coplanar surfaces.
  • Describe the part characteristics being controlled when profile of a surface is applied to coplanar surfaces.
  • Describe two common applications for a profile of a surface control.
  • Describe how a profile of a surface control can be inspected.

Lesson 28: Profile of a Line
Goal: Interpret the profile of a line control.

  • List two requirements of a profile of a line control.
  • Describe the tolerance zone for a profile of a line control.
  • Describe how profile of a line is view dependent.
  • Interpret a multiple single-segment profile application.
  • Interpret an application with a profile of a line control used with coordinate tolerances.
  • Describe two common applications for a profile of a line control.
  • Describe how profile of a line can be inspected.

 



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This file last modified 12/24/13