ISO 14405:2016

Description

ISO 14405-1:2016 establishes the default specification operator (see ISO 17450‚Äë2) for linear size and defines a number of special specification operators for linear size for features of size, e.g. “cylinder”, “sphere”, “torus,”[1], “circle”, “two parallel opposite planes”, or “two parallel opposite straight lines”.

It also defines the specification modifiers and the drawing indications for these linear sizes.

It covers the following linear sizes:

a) local size:

– two-point size;

– spherical size;

– section size;

– portion size;

b) global size:

– direct global linear size:

– least-squares size;

– maximum inscribed size;

– minimum circumscribed size;

– minimax size;

– indirect global linear size;

c) calculated size:

– circumference diameter;

– area diameter;

– volume diameter;

d) rank-order size:

– maximum size;

– minimum size;

– average size;

– median size;

– mid-range size;

– range of sizes;

– standard deviation of sizes.

ISO 14405-1:2016 defines tolerances of linear sizes for the following:

– a + and/or ‚àí limit deviation (e.g. 0/‚àí0,019);

– an upper limit of size (ULS) and/or lower limit of size (LLS) (e.g. 15,2 max., 12 min., or 30,2/30,181);

– an ISO tolerance class code in accordance with ISO 286‚Äë1 (e.g. 10 h6);

with or without modifiers.

ISO 14405-1:2016 provides a set of tools to express several types of size characteristic. It does not present any information on the relationship between a function or a use and a size characteristic.

[1] A torus is a feature of size when its directrix diameter is fixed.