Examples of tolerance zone
Single geometric tolerances:
Straightness tolerance specifies a tolerance zone bound by two parallel lines.
During inspection measurements could be obtained by the use of a dial indicator in conjunction with other basic measuring tools. Alternatively a line could be probed on the surface using a CMM.
Related geometric tolerances:
Tolerances of location indicate the permissible variation in the location of a feature in relation to another feature or datum (location, symmetry and concentricity) Basic dimensions establish the true position from datum features and betrween interrelated features.
Positional tolerance is the total permissible variation in a location of a feature about its theoretically exact location with respect to the datum. For cylindrical feature, such as holes and outside diameters, the positional tolerance is generally the diameter of the tolerance zone in which the axis of the feature must lie.
The tolerance zone is defined by a cylinder of diameter 0.375 mm. The axis of the cylindrical tolerance zone is set relative to datum B and datum C.
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Good practice online modules
- Dimensional
- Overview of basic design and interpretation of an engineering drawing
- An introduction to datum
- An introduction to geometric tolerancing
- An introduction to the designer's role when designing a component
- An introduction to the manufacturer's role when designing a component
- An introduction to the inspector's role when designing a component