Geometric Dimensioning and Tolerancing

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Geometric Dimensioning and Tolerancing
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MIL-HBK-727
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MIL-HBK-727
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MIL-HBK-727
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Feature Control Frame
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(No Transcript)
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Datums
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(No Transcript)
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(No Transcript)
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Rule 1-Indivdual Feature of Size

• Where only a tolerance of size is specified, the
  limits of size of an individual feature prescribe
  the extent to which variations in geometric form,
  as well as size, are allowed. (ASTM Y14.5-2009).
• Meaning?

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51
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101
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Engineering Design Communication Lockhart and
Johnson
Fundamentals of Graphics Communication
Bertoline and Weibe
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Engineering Design Communication Lockhart and
Johnson
Fundamentals of Graphics Communication
Bertoline and Weibe
14
Engineering Design Communication Lockhart and
Johnson
Fundamentals of Graphics Communication
Bertoline and Weibe
15
Engineering Design Communication Lockhart and
Johnson
Fundamentals of Graphics Communication
Bertoline and Weibe
16
Engineering Design Communication Lockhart and
Johnson
Fundamentals of Graphics Communication
Bertoline and Weibe
17
Engineering Design Communication Lockhart and
Johnson
Fundamentals of Graphics Communication
Bertoline and Weibe
18
Engineering Design Communication Lockhart and
Johnson
19
Fundamentals of Graphics Communication
Bertoline and Weibe
20
Fundamentals of Graphics Communication
Bertoline and Weibe
21
Fundamentals of Graphics Communication
Bertoline and Weibe
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Summary

• All dimensions include controls of geometry.
  Rule 1 states that a size control inherently
  includes controls of form.
• Because of Rule 1, the need for GDT callouts is
  minimized. Use carefully.
• GDT should be used to refine the relationship
  between feature and form.
• GDT should open tolerances. MMC should reduce
  part cost.

Technical Graphics Communication, Bertoline, et al