The document discusses geometric dimensioning and tolerancing (GD&T), an international language for accurately describing part specifications in engineering drawings. It outlines fundamental concepts, symbols, and rules used to communicate size, form, and tolerances, aimed at enhancing design clarity and manufacturing precision. Additionally, it highlights the American Society of Mechanical Engineers (ASME) standards that govern GD&T practices.

1. GD&T: An
International
Language
GD&T: An Exact
Language
GD&T Provides
Uniformity

2.  GD&T stands for Geometric Dimensioning and Tolerancing,
as defined by ASME Y14.5M-1994.
 GD&T: An International Language
Geometric dimensioning and tolerancing is an international language
used on drawings to accurately describe a part. The language
consists of a well-defined set of symbols, rules, definitions, and
conventions that can be used to describe the size, form,
orientation, and location tolerances of part features.
 GD&T: An Exact Language
Geometric tolerancing is an exact language that enables designers
to “say what they mean” on a drawing, thus improving product
designs. Production uses the language to interpret the design
intent, and inspection looks to the language to determine set up.
 GD&T Provides Uniformity
By providing uniformity in drawing specifications and
interpretation, GD&T reduces controversy, guesswork, and
assumptions throughout the manufacturing and inspection process.

3. (Based on ASME Y14.5M-1994)

4. Provide Participants with
Fundamental concepts of
GDnT
Enable Participants to
express, understand and
interpret drawing
requirements using GDnT
to ANSI / ASME Y14.5M
Stdandards.
(Based on ASME Y14.5M-1994)

5. ASME, American Society of Mechanical Engineers.
Founded in 1880 by Alexander Lyman Holley, Henry Rossiter Worthington, John Edison
Sweet and Matthias N. Forneyin response to numerous steam boiler pressure vessel
failures.
ASME is an engineering society focused on mechanical engineering in North America, is
thus a standards organization, a research and development organization, a provider of
training and education, and a nonprofit organization.
- A document that communicates a precise description of a part.
- This description consists of pictures, words, numbers, and symbols.

6. Day 1 The Definitions
 Datums
Datum feature system (planar datum)
Datum Feature Simulator, Datum targets
 Dimension
Basic and Reference,
Using Basic Dimension
Envelop, actual mating
 Feature
Control frame, axis Of, Center of Plane, Size
FIM, MMC, LMC,RFS Conditions
 Size
Actual, Nominal & Virtual
 Tolerance of Position Controls
Bilateral, Geometric, Unilateral, of position
True Geometric Counterpart
(Based on ASME Y14.5M-1994)

7. Day 2
 Fundamental Rules
Dimensioning & Tolerancing
Selection & arrangement to suit Function and mating relationship
Rule #1 and Rule #2
Basic dimensions, virtual condition, bonus tolerance
 Position Controls
Concentricity, Symmetry
 Profile Controls
Profile tolerancing
Profile of a surface
Profile of a line
 Workshop
Drawing Interpretation
Presentation
Q & A Discussion
Closing comments

8.  The
definitions

9. Datum Feature Simulator - The inspection equipment (or
gage surfaces) used to establish a datum.
Datum Reference Frame - A set of three mutually
perpendicular datum planes.
Datum Shift - The allowable movement, or looseness,
between the part datum feature and the gage.
Datum System - A set of symbols and rules that
communicate to the drawing user how dimensional
measurements are to be made.

10. Datum - A theoretically exact plane, point or axis from which
a dimensional measurement is made.
Datum Feature - A part feature that
contacts a datum.
Datum Target - A symbol that describes the
shape, size, and location of gage elements
that are used to establish datum planes or
axes.

11. Basic Dimension - A numerical value used to
describe the theoretically exact size, true
profile, orientation, or location of a feature or
datum target.
Between Symbol - A double ended arrow that
indicates the tolerance zone extends to
include multiple surfaces.
Dimension - A numerical value expressed in appropriate
units of measure and used to define the size, location,
orientation, form, or other geometric characteristics of a part.

12. .
Feature - A general term applied to a physical portion of a
part, such as a surface, hole, or slot.
Feature Control Frame - A rectangular box
that is divided into compartments within which
the geometric characteristic symbol, tolerance
value, modifiers, and datum references are
placed
Feature of Size - One cylindrical or spherical surface, or a set of
two opposed elements or opposed parallel surfaces, associated
with a size dimension.
Feature of Size Dimension - A dimension that is associated with a
feature of size.

13.  Datum New Activities

14. You!
End of Day 1

15. Review Day 1, The
Definitions
 Datums
Datum feature system (planar datums)
Datum Feature Simulator, Datum targets
 Dimension
Basic and Reference, Using Basic Dimension
Envelop, actual mating
 Feature
Control frame, axis Of, Center of Plane, Size
FIM, MMC, LMC,RFS Conditions
 Size
Actual, Nominal & Virtual
 Tolerance of Position Controls
Bilateral, Geometric, Unilateral, of position
True Geometric Counterpart

16. Datum - A theoretically exact plane, point or axis from which
a dimensional measurement is made.
Datum Feature - A part feature that
contacts a datum.
Datum Target - A symbol that describes the
shape, size, and location of gage elements
that are used to establish datum planes or
axes.

17. Datum Feature Simulator - The inspection equipment (or
gage surfaces) used to establish a datum.
Datum Reference Frame - A set of three mutually
perpendicular datum planes.
Datum Shift - The allowable movement, or looseness,
between the part datum feature and the gage.
Datum System - A set of symbols and rules that
communicate to the drawing user how dimensional
measurements are to be made.

18. Basic Dimension - A numerical value used to
describe the theoretically exact size, true
profile, orientation, or location of a feature or
datum target.
Between Symbol - A double ended arrow that
indicates the tolerance zone extends to
include multiple surfaces.
Dimension - A numerical value expressed in appropriate
units of measure and used to define the size, location,
orientation, form, or other geometric characteristics of a part.

19. .
Feature - A general term applied to a physical portion of a
part, such as a surface, hole, or slot.
Feature Control Frame - A rectangular box
that is divided into compartments within which
the geometric characteristic symbol, tolerance
value, modifiers, and datum references are
placed
Feature of Size - One cylindrical or spherical surface, or a set of
two opposed elements or opposed parallel surfaces, associated
with a size dimension.
Feature of Size Dimension - A dimension that is associated with a
feature of size.

20. Day 2
 Fundamental Rules
Dimensioning & Tolerancing
Rule #1 and Rule #2
Basic dimensions
 Profile Controls
Profile tolerancing
 Workshop
Drawing Interpretation
Presentation
Q & A Discussion & Closing comments

21. Dimensioning & Tolerancing
Selection & arrangement to suit
Function and mating relationship
Rule #1 and Rule #2

22. Profile tolerancing
Profile of a surface
Profile of a line

23.  Drawing Interpretation
 Presentation
 Q & A Discussion

27. You!