Training Title: 3-Day “Basics of GD&T”
COURSE CONTENTS
GD&T Introduction
What is GD&T? Why use GD&T?
How does GD&T work?
Comparison of GD&T with CD&T (Coordinate Dimensioning and Tolerancing)
Part Features, Feature of Size, Non-size Features
What are Part Features?
Features of Size
Non-Size Features
14 GD&T Symbols
Feature Control Frame(FCF) and its placement
How to read FCFs?
Modifier symbols: MMC, LMC, RFS
When to use MMC, LMC and RFS modifier in design (correct applications)
Bonus tolerance calculations
Rule # 1 and Rule # 2
Tolerances Zones
Virtual Condition Boundary
Importance of Virtual condition in designs
Virtual condition calculations on MMC basis
Use virtual condition for mating parts as well to design fixed gauges
100% interchangeability guarantee in design phase itself by using virtual condition correctly
Class room exercise for virtual condition
Form Tolerances
Flatness tolerance
Straightness tolerance
Circularity Tolerance
Cylindricity Tolerance
When to use Form Tolerance?
Relationship between Rule # 1 and form tolerance controls
Inspection methods to verify form tolerances
Design recommendation on why to use form tolerances only when required to ensure successful
design intent
Datums
What is datum?
Six Degrees of Freedom
Datum Reference Frame (Cartesian coordinate system)
Datum Feature Selection, Functional Hierarchy
Datum feature identification / placements and interpretation
Datum plane, datum axis, Datum center plane
Physical datum feature simulators
3-2-1 principle
Datum feature qualification
Importance of Datum Precedence
Select datum features according to the design intent
Orientation Tolerances
How it works? How to apply it?
Perpendicularity tolerance
Parallelism tolerance
Angularity tolerance
Applied to a planar feature
Applied to feature of size
When do we use Orientation Tolerance?
Datums for Orientation Control
Inspection methods to verify orientation tolerances
Difference between parallelism and Flatness
Class room exercise for orientation tolerance
Location Tolerances:
A) Position Tolerance
How it works? How to apply it?
Tolerance zone shapes
Position tolerance for cylindrical features on MMC, LMC and RFS basis
Detailed table calculations for position tolerance on MMC, LMC and RFS
Position on Boundary basis for rectangular or oblong slots
Zero tolerance at MMC basis
Datums for Position Control
Inspection methods to verify position tolerances
Class room exercise for position
B) Runout Tolerances
How it works? How to apply it?
Circular Runout Tolerance
Total Run out Tolerance
Datums for Run out Controls
Inspection methods to verify runout tolerances
C) Profile Tolerances
How it works? How to apply it?
Profile of a Line Tolerance
Profile of a Surface Tolerance
4 types of Profile Tolerance Zone
Bi-lateral
Unilateral - IN (Un-equally Disposed)
Unilateral - OUT(Un-equally Disposed)
Bi-lateral Un-equal(Un-equally Disposed)
Controlling extent of profile tolerance
Datums for Profile Controls
Inspection methods to verify Profile tolerances
Class room exercise for profile
D) Concentricity & Symmetry Tolerances
How it works? How to apply it?
Concentricity Tolerance
Symmetry Tolerance
Tolerance zone shapes
Datums for concentricity & symmetry controls
Inspection methods to verify concentricity & symmetry tolerances
Why to avoid using Concentricity and Symmetry for small and inexpensive part designs
Case Studies & Review of “Your Company” drawings:
Case studies in general and specific to your company / products
Review existing Your Company drawings
Discussion on the correct and incorrect use of GD&T on your existing drawings
GD&T best practices for inspection and manufacturing
Understand the internal competition between 14 GD&T symbols and select the most appropriate and
inexpensive GD&T symbol.
Contact:
Mr. Swapnil Gujarathi
Senior GD&T Trainer (ASME-USA Certified)
CADSaga Consultancy Services
L-8, Suyojit Sankul, Sharanpur Road
Nashik - 422002
Contact: 90110 81591
www.cadsaga.com swapnil@cadsaga.com
