BS EN ISO 14405-2:2019

What is ISO 14405-2 - Geometrical product specifications about?

ISO 14405-2 is the second part of an international multi-series standard that covers Geometrical product specifications (GPS).

ISO 14405-2 illustrates the ambiguity caused by the use of dimensional specifications to control properties other than linear or angular size and the benefit of using geometrical specifications instead.

ISO 14405-2 specifies technicalities for dimensional tolerancing such as related terms and definitions, principles, rules for indication of dimensions and other related tolerances, units used in drawings for dimensions, the indication of tolerances for linear or angular dimensions, illustrations of ambiguous ± tolerancing vs. unambiguous geometrical specifications, angular tolerancing, etc.  

Who is ISO 14405-2 - Geometrical product specifications for?

ISO 14405-2 on the Geometrical product specifications is beneficial for:

• Engineers and mathematicians
• An entity responsible for providing geometrical support
• Engineering graphical designers
• Production workers
• Metrologists

Why should you use ISO 14405-2 - Geometrical product specifications?

For dimensions other than linear or angular sizes, the requirement is ambiguous when applied to the real workpiece. It is the presence of form and angular deviations on all real workpieces that makes these requirements ambiguous, i.e., there is a specification ambiguity. Geometrical product specifications (GPS) define the nominal geometry of the components that make up the product.

ISO 14405-2 is a geometrical product specification (GPS) standard and is to be regarded as a general GPS standard. It influences chain-link A of the chain of standards on distance.

ISO 14405-2 shows the uses of geometrical specifications for dimensions that are not linear sizes, or angular sizes to avoid the ambiguity that the use of ± tolerances on this type of dimensions causes.

ISO 14405-2 updates the user about the ambiguity caused by using ± tolerances for dimensions other than linear sizes or angular sizes.

ISO 14405-2 is a part of the ISO/GPS matrix model that gives an overview of the ISO/GPS system. It applies the fundamental rules and the default decision rules of ISO/GPS unless otherwise indicated.

What’s changed since the last update?

BS EN ISO 14405-2: 2019 supersedes BS EN ISO 14405-2:2011, which is withdrawn. The main changes compared to the previous edition are as follows:

• The addition of angular sizes to reflect ISO 14405-3
• Clarifications around specification ambiguity and the use of geometrical tolerancing
• A review and update of all normative references and other ISO GPS standards referenced in the text.