1. Tolerance zone position

The evaluation of defects in shape, orientation and position requires the spatial positioning of the tolerance zone within which the specified element must lie. As we shall see, this positioning is carried out with varying degrees of constraint.

• Form tolerance

  Example

  flatness of a surface (figure 1 )

  Interpretation: as seen previously, and as shown in figure 1 b, the actual surface must lie within the area defined by two parallel planes, t = 0.02 mm apart.

  Position of the tolerance zone: if the actual...