Nominal size dimensions (linear dimensions, two-point dimensions) for limit deviations according to Table 2 of ISO 20457/DIN 16742 are tolerance center dimensions for drawings and CAD data sets.

DP-Dimmensions (distance dimensions) according to ISO 20457/DIN 16742 are nominal dimensions for position tolerances according to Table 9 and for profile shape tolerances according to Table 10 with the following definition:

„A component can have one or more reference systems. To determine the profile shape and position tolerance, the longest distance of the tolerated element to the origin of the reference system (DP dimension) used for profile shape and position tolerance shall be used. This does not have to match the coordinate system of the part or assembly.“ 

An example of position tolerance is given in Appendix G of ISO 20457/DIN 16742.

For tolerating the distance of parallel surfaces which are not directly opposite each other but are arranged offset from each other, the DP dimension for limit dimensions according to Table 9 of ISO 20457/DIN 16742 is provided as the nominal size dimension. Furthermore applies:

  • Nominal dimensions below 1 mm and above 1000 mm are subject to agreement.
  • For general tolerances, only the limit dimensions for moulded part dimensions that are not tool-bound apply.
  • Limiting dimensions for wall thicknesses are subject to agreement.
  • General tolerances shall be specified in the design documentation as follows: Example: DIN 16742 ─ TG6.