GD&T
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system for setting communicatating tolerances
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uses symbols and notatinos
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Describes
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nominal geometry of parts
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Accapteble range in size, shap direcetion and position of each feature
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How features can deviate in relation to each within acceptable limits
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Standards
Nomenclature
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Basic or nominal size:
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the ttheoretical dimenitions of a feature
Clearance and interference fits
- suppose we have a max hole diameter and a minimum hole diameter
- and we have a maximum shaft diameter and a minimum shaft diameter
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calculating the clearance
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- maximum clearance= max hole diameter - min shaft diameter
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- minimuma clearance = min hole diameter - max shaft diameter
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Fit chart
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Shaft hole
- Shaft is lowercase
- hole is uppercase
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A-P
- A is the most lose
- P is the most tight
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6-9
- 6 is most accurate
- 9 is most rough
Feature control frame
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Parts of the feature control frame
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Geometric tolerancing symbols
