ISO 20457/DIN 16742 is used to determine production-related possible tolerances (manufacturing tolerances) and for comparison with functional tolerances in order to check the attainability of a dimensional accuracy required by the design.


Detected tolerances: Limit deviations for size dimensions (two-point dimensions) as indirect tolerance (general tolerances) and as direct tolerance (dimension given on the nominal size dimension). 


For tolerating deviations in shape and position with profile shape tolerances as general tolerances and position tolerances for direct tolerance through cylindrical tolerance zones.


Process engineering basics: original moulding process with tools closed on all sides, such as injection moulding, injection embossing, injection moulding and pressing of non-porous moulded parts made of thermoplastics, thermoplastic elastomers and thermosets as well as rotational moulding of thermoplastics. For special process variants of the above-mentioned processes, the standard can be applied analogously after agreement with the molding manufacturer.


Not normatively recorded: Porous moulding materials (e.g. foams) and other processing and machining methods. The same also applies to process combinations of original forming and forming processes (e.g. injection blow molding, injection stretch molding).


Deviations from the surface quality of the molded part, such as sink marks, unwanted flow structures and roughness as well as weld lines are not the subject of the standard.


If tolerances outside the scope of the standard are required, these must be agreed with the manufacturer of the moulded part and specified in the drawing.