scope:

This part of ISO 14405 establishes the default specification operator (see ISO 17450‑2) 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.

This part of ISO 14405 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. This part of ISO 14405 defines tolerances of linear sizes for the following:

- a + and/or − limit deviation (e.g. 0/−0,019) (see Figure 11);

- 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) (see Figure 13); 

 an ISO tolerance class code in accordance with ISO 286‑1 (e.g. 10 h6) (see Figure 12); with or without modifiers (see Tables 1 and 2).

This part of ISO 14405 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