BS EN ISO 5458:2015 pdf free

BS EN ISO 5458:2015 pdf free.Geometrical product specifications (GPS)一Geometrical tolerancing一Positional and pattern tolerancing
By default, based on the independency principle defined in ISO 8015, a geometrical specification of form,orientation, location or run-out, without modifier, applied to n geometrical features (n being greater than one),is equivalent to n independent geometrical specifications: each geometrical feature shall be considered individually and each specification shall be considered individually (independent between them). The resulting independent tolerance zones correspond to an implicit indication of the SZ (separate zones) modifier: the “all around” modifier does not create itself a united feature or a pattern.
When positional tolerancing is applied to several geometrical features and all the non-redundant degrees of freedoms of the tolerances zones are un-locked, either the SZ (separate zones) modifier or the CZ (combined zone) modifier shall always be indicated in the second compartment of the tolerance indicator.
NOTE This rule allows the potential conflict of interpretation between ISO 1101 :2012 and the former ISO 5458:1998 to be resolved (see Annex B).
一to manage the orientation constraints and the location constraints, the modifier CZ (combined zone) shall be indicated, and these shall be defined by linear and angular TEDs (implicit or explicit).
一to manage the orientation constraints only, the following order of modifiers CZ (combined zone) and”> <“(orientation only) shall be indicated, and these orientation constraints shall be defined by angular TEDs (implicit or explicit).
When a geometrical symbol (form, orientation, location (e.g. position), or run-out symbol) is used in the tolerance indicator without indication of a datum, CZ shall be indicated in the second compartment of the tolerance indicator. This rule consolidates the general rules, to use CZ when it is necessary to create a collection of tolerance zones with orientation and location constraints defined between them (see Figure 4 and former practice in Annex A).
When more than one single feature (complete or not) is the subject of a same geometrical specification, and the modifier CZ is indicated in its second compartment, the toleranced feature consists of the collection of the considered geometrical features and the tolerance zone is a combined zone consisting of the set of individual zones constrained between them in orientation and location.BS EN ISO 5458 pdf free download.