ISO 21940-12:2016

Mechanical vibration - Rotor balancing - Part 12 : procedures and tolerances for rotors with flexible behaviour

ISO 21940-12:2016 presents typical configurations of rotors with flexible behaviour in accordance with their characteristics and balancing requirements, describes balancing procedures, specifies methods of assessment of the final state of balance, and establishes guidelines for balance quality criteria.

ISO 21940-12:2016 can also serve as a basis for more involved investigations, e.g. when a more exact determination of the required balance quality is necessary. If due regard is paid to the specified methods of manufacture and balance tolerances, satisfactory running conditions can be expected.

ISO 21940-12:2016 is not intended to serve as an acceptance specification for any rotor, but rather to give indications of how to avoid gross deficiencies and unnecessarily restrictive requirements.

Structural resonances and modifications thereof lie outside the scope of this part of ISO 21940.

The methods and criteria given are the result of experience with general industrial machinery. It is possible that they are not directly applicable to specialized equipment or to special circumstances. Therefore, in some cases, deviations from this part of ISO 21940 are possible.

To comply with a standard, you need to quickly understand its issues in order to determine its impact on your activity.

The Requirements department helps you quickly locate within the normative text:
- mandatory clauses to satisfy,
- non-essential but useful clauses to know, such as permissions and recommendations.

The identification of these types of clauses is based on the document “ISO / IEC Directives, Part 2 - Principles and rules of structure and drafting of ISO documents ”as well as on a constantly enriched list of verbal forms.

With Requirements, quickly access the main part of the normative text!

The Redline + service - standards comparator allows you to easily and simply identify major changes between the current standard and its last canceled version.

At a glance, you will be able to identify the additions, deletions or modifications to a text, table, figure and formula.


The Redlines + service is offered to you on the collection of French standards in force, in French language and in HTML and PDF format.

For an overview of the service, click on View a standard in redline format

COBAZ is the simple and effective solution to meet the normative needs related to your activity, in France and abroad.

Available by subscription, CObaz is THE modular solution to compose according to your needs today and tomorrow. Quickly discover CObaz!

Request your free, no-obligation live demo

I discover COBAZ