TS 300

TS 300 is a guidance standard on the use of preferred numbers and preferred number series. In engineering and technical design, this approach helps replace ad hoc numerical choices with orderly series steps so that dimensions, capacities and ratings can be selected in a consistent and economical way.

What preferred numbers are for

Preferred numbers provide a common numerical basis for standardization. From a general technical perspective, they help reduce unnecessary variety, divide ranges in a more systematic way, and make it easier to match related equipment, sizes and performance classes. Such series are especially useful where nominal values, tolerances and graded ratings need to be organised coherently.

The scope of this standard is the use of preferred numbers and preferred number series; it addresses the logic of choosing numerical values rather than defining a specific product type. Based on equivalence with ISO 17, it reflects an internationally recognised framework for these series and sits in relation to TS 299 within the same broader numbering and quantities context.

• Selecting technical values in regular numerical steps
• Aligning size and capacity increments
• Reducing variety through standardised series logic
• Choosing comparable values for design and production