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Positional Tolerance

 
Position defines a zone within the axis or centre plane of a feature is permitted to vary from true position position.
 
The tolerance range is the range contained within a circle or sphere of diameter t with its centre situated at the theoretically exact location of the considered point (hereafter referred to as the "true location").
 
The point shown by the indicator line shall be contained within a 0.03mm diameter circle with its centre situated at the true location 60mm from datum line A and 100mm from datum line B.
 
Tolerance of position control is used to define the location of a feature of size. It defines a zone within which the axis, median plane, or surface of a feature-of-size is permitted to vary from a true (theoretically exact) position. Tolerance of position (TOP) also indirectly controls the orientation (generally perpendicularity or parallelism) of a FOS (feature of size) relative to the primary datum specified in the feature control frame.
 
Position is a condition in which the accuracy of location for a single feature or a pattern of feature of size is defined in relation to datums that are determined based upon the geometric relationship and design requirements.
 
True Position is the theoretically exact location of a FOS as defined by basic dimensions.
 
Position tolerance control is a 3D control.

 

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