GEOMETRIC DIMENSIONING AND TOLERANCING GDT

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GEOMETRIC DIMENSIONING AND TOLERANCING (GDT)

• Dr. Jack Zhou
• Department of Mechanical Engineering and
  Mechanics
• Drexel University, Philadelphia, PA

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SYMBOLS ABBREVIATIONS
Geometric Characteristics Symbols
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DATUM REFERENCING
Datum Reference Frame
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DATUM FEATURE SYMBOL
Datum Feature
Datum Feature Symbol
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DATUM FEATURE SYMBOL (Cont)
Feature Surface and extension line
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DATUM FEATURE SYMBOL (Cont)
When the datum is the axis or center plane
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DATUM FEATURE SYMBOL (Cont)
When the datum is the axis
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DATUM FEATURE SYMBOL (Cont)
Where no geometrical tolerance and feature
control frame used
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DATUM FEATURE SYMBOL (Cont)
When the feature controlled is the datum
axis/datum center plane
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MAXIMUM MATERIAL CONDITION
.03 -.025
MMC
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LEAST MATERIAL CONDITION
.03 -.025
LMC
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Straightness
TOLERANCES OF FORM
Straightness Tolerance Zone
Straightness Tolerance
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TOLERANCES OF FORM
Flatness
Flatness Tolerance Zone
Flatness Tolerance
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TOLERANCES OF FORM
Circularity
Circularity Tolerance Zone
Circularity Tolerance
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TOLERANCES OF FORM
Cylindricity
Cylindricity Tolerance Zone
Cylindricity Tolerance
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TOLERANCES OF ORIENTATION
Perpendicularity
Perpendicularity Tolerance Zone
Perpendicularity Tolerance
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TOLERANCES OF ORIENTATION
Angularity
Angularity Tolerance Zone
Angularity Tolerance
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TOLERANCES OF ORIENTATION
Parallelism
Parallelism Tolerance Zone
T Tangent Plane
Parallelism Tolerance
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TOLERANCE OF PROFILE
Profile
Profile Tolerance Zone of Line
Profile Tolerance of Line
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TOLERANCE OF PROFILE (Cont)
Profile (Cont)
Profile Tolerance of Surface
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TOLERANCE OF RUNOUT
Runout
Circular Runout Tolerance Zone
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TOLERANCE OF RUNOUT (Cont)
Runout (Cont)
Circular Runout Tolerance
Total Runout Tolerance
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TOLERANCE OF LOCATION
Concentricity
Concentricity Tolerance Zone
Concentricity Tolerance
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TOLERANCE OF LOCATION
Position
Position Tolerance Zone
Position Tolerance
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TOLERANCE OF LOCATION
Symmetry
Symmetry Tolerance Zone
Symmetry Tolerance
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Quiz

• 1. Find TH, Ts, Tf, Cmax, Cmin, and what kind of
  fit it is ?
• Hole F 66 upper deviation 0.051, lower deviation
  0.0
• Shaft F 66 upper deviation -0.024, lower
  deviation -0.050
• 2. Find TH, Ts, Tf, Cmax, Imax, and what kind of
  fit it is ?
• Hole F 32 upper deviation 0.021, lower deviation
  0.0
• Shaft F 32 upper deviation 0.029, lower
  deviation 0.016
• 3. If a shaft is 100.05 inch what is its maximum
  and least material conditions.
• 4. Please draw circularity and perpendicularity
  symbol blocks with geometric
  tolerance of 0.005 for each, and sketch their
  tolerance zones for a cylinder and a upside down
  T shape block, respectively.

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Quiz

• If a shaft is 100.05 inch what is its maximum
  and minimum material conditions.
• Please draw circularity and perpendicularity
  symbol blocks and tolerance zones for a cylinder
  and a upside down T shape block, respectively.

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