4. Geometric specifications

4.1 General

There are four main types of geometric specifications defined in ISO 1101 :

• geometric shape specifications ;

• geometric orientation specifications ;

• geometric position specifications ;

• geometric runout specifications.

A geometric specification is used to describe a requirement by defining :

• the toleranced element (the geometric element to be observed) ;

• the tolerance zone with or without orientation or position constraints.

The tolerance zone is the area of variation allowed...