ISO 14405-3:2016 Preview

ISO 14405-3:2016 establishes the default specification operator for angular size and defines a number of special specification operators for features of angular size: cone (truncated, i.e. frustum, or not), wedge (truncated or not), two opposite straight lines (intersection of a wedge/truncated wedge and a plane perpendicular to the intersection straight line of the two planes of the wedge/truncated wedge, intersection of a cone/frustum and a plane containing the axis of revolution of the cone/frustum). See Figure 1 and Figure 2.

ISO 14405-3:2016 also defines the specification modifiers and the drawing indications for these angular sizes.

ISO 14405-3:2016 covers the following angular sizes:

- local angular size:

• - angular size between two lines;
• - portion angular size;

- global angular size:

• - direct global angular size:
• - least squares angular size;
• - minimax angular size;
• - rank order angular size/indirect global angular size:
• - maximum angular size;
• - minimum angular size;
• - average angular size;
• - range of angular sizes;
• - mid-range angular size;
• - median angular size;
• - standard deviation of angular size.

ISO 14405-3:2016 defines the meaning of tolerances of angular sizes indicated as

- + and/or - limit deviations, e.g. 0°/-0,5°, or

- indicated with upper limit of size (ULS) and/or lower limit of size (LLS), e.g. 35° max. or 15° min., 34°/36°,

- with or without modifiers.

ISO 14405-3:2016 provides a set of tools to express several types of angular size characteristics. It does not give any information on the relationship between a function or a use and an angular size characteristic.