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12Practical Applications and
Calculation Methods
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
• Calculate position tolerances when more than two parts are stacked in a floating fastener or fixed fastener application.
• Distribute the total available position tolerance between features to which position tolerances are applied.
• Specify projected tolerance zones for fixed feature locations to prevent interference conditions.
• Determine the amount of tolerance accumulation in a simple assembly.
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
• Properly use zero position tolerances at MMC to increase manufacturing freedom.
• Apply paper gaging techniques to determine if a produced part meets drawing requirements.
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Floating Fastener Condition—Two Stacked Parts
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Floating Fastener Condition—Three Stacked Parts
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Floating Fastener Condition— Two Hole Sizes & Distributed Tolerances
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Fixed Fastener Condition—Two Stacked Parts
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Fixed Fastener Condition—Two Parts, Unevenly Distributed Tolerances
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Fixed Fastener Condition—Projected Tolerance Zone
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Zero Position Tolerance at MMC
• Zero tolerancing at MMC increases manufacturing freedom
• Clearance conditions must exist• Located feature must have a size tolerance• Lets the manufacturer choose how to allocate
the tolerances
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Zero Position Tolerance at MMC Application
GD&T: Application and Interpretation © Goodheart-Willcox Co., Inc.
Paper Gaging Techniques
• Measure hole locations relative to datum reference frame
• Calculate coordinate variations• Calculate diameter position variations• Plot coordinate variation values