Geometric tolerances: A new application for line geometry and screws

J. K. Davidson, J. J. Shah

Research output: Contribution to journalArticlepeer-review

42 Scopus citations


A new mathematical model is introduced for the tolerances of cylindrical surfaces. The model is compatible with the ISO/ANSI/ASME standard for geometric tolerances. Central to the new model is a Tolerance-Map®▲, a hypothetical volume of points that corresponds to all possible locations and variations of a segment of a line (the axis) that can arise from tolerances on size, location and orientation of the cylindrical surface. Each axis in a tolerance zone will be represented with the six Plücker coordinates. Cylindrical surfaces in a tolerance zone for the same hole can then be treated by attaching a size tolerance to each of the lines, thereby forming a screw. Relationships for the content of line solids for a tolerance zone are developed to correspond to the variations of locations. These are then used to obtain a measure for the increment in cost when a more refined tolerance is specified. This model is one part of a bilevel model that is under development for geometric tolerances.

Original languageEnglish (US)
Pages (from-to)95-104
Number of pages10
JournalProceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science
Issue number1
StatePublished - 2002


  • Geometric tolerances
  • Line geometry
  • Screws
  • Tolerancing

ASJC Scopus subject areas

  • Mechanical Engineering


Dive into the research topics of 'Geometric tolerances: A new application for line geometry and screws'. Together they form a unique fingerprint.

Cite this