BS EN ISO 5458:2015 pdf download.Gcomentrical Product Specifcations (GPS) - Geometrical tolerancing - Positional and patterm tolerancing.
By default, based on the independency pnnciple defined in ISO 8015, a geometrical speoficatlon ol form, orientation, location or runout, 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 implcit indloalion of the SZ (separate zones) modifier: the mall around” modifier does not create itself a united feature or a pattern.
When positional tolerancrng is applied to several geometrical features and aN 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 in&ated in the second compartment of the tolerance indicator.
NOTE INs rule alws the potential conflict of interpretation between ISO I tOt :2012 and the former ISO 5458:1996 to be resolved (see Annex B)
To create one homogeneous pattern, the modilier CZ shall be Indicated In me tolerance section of the tolerance indicator.
To cfeate a new level of pattern defined as a homogeneous pattern of more than one homogeneous patterns, an additional CZ modifier shall be indicated after the sequence defining the previous level of pattern.
EXAMPLE One CZ in the tolerance section defines a singe pattern The sequence CZ CZ CZ in the tolerance section defines a pattern of patterns ci patterns Ipatlern of level three).
When positional tolerancrng is applied to several geometrical features and aN 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 in&ated in the second compartment of the tolerance indicator.
NOTE INs rule alws the potential conflict of interpretation between ISO I tOt :2012 and the former ISO 5458:1996 to be resolved (see Annex B)
To create one homogeneous pattern, the modilier CZ shall be Indicated In me tolerance section of the tolerance indicator.
To cfeate a new level of pattern defined as a homogeneous pattern of more than one homogeneous patterns, an additional CZ modifier shall be indicated after the sequence defining the previous level of pattern.
EXAMPLE One CZ in the tolerance section defines a singe pattern The sequence CZ CZ CZ in the tolerance section defines a pattern of patterns ci patterns Ipatlern of level three).
