12 Practical 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 Projected Tolerance Zone

GD&T: Application and Interpretation© Goodheart-Willcox Co., Inc. Zero Position Tolerance at MMC Zero tolerancing at MMC increases manufacturing freedomZero tolerancing at MMC 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

GD&T: Application and Interpretation© Goodheart-Willcox Co., Inc. Projected tolerance zone –A tolerance zone that extends to the outside of the controlled feature. Zero tolerancing at MMC –A position tolerance that shows no tolerance in the feature control frame, but instead places all the tolerance on the size of the located feature. This permits maximum flexibility in manufacturing if properly done.