# ISO 21940-21:2012 — Withdrawn and superseded ISO standards

For ISO 21940-21:2012, item title is Mechanical vibration —  Rotor balancing — Part 21: Description and evaluation of balancing machines; status code is 9599; successor is ISO 21940-21:2022; withdrawn / published date is 2012-07-10, recorded from its source on 2026-08-05.

- **Identifier:** ISO 21940-21:2012 _(verified: appears in the quote below)_
- **Item title:** Mechanical vibration —  Rotor balancing — Part 21: Description and evaluation of balancing machines _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** ISO 21940-21:2022
- **Withdrawn / published date:** 2012-07-10 _(verified: appears in the quote below)_

## What the source says

> 56562,IS,,ISO 21940-21:2012,Mechanical vibration — Rotor balancing — Part 21: Description and evaluation of balancing machines,Vibrations mécaniques — Équilibrage des rotors — Partie 21: Description et évaluation des machines à équilibrer,2012-07-10,1,['21.120.40'],ISO/TC 108/SC 2,9599,[1733],[78146],['en'],53,"<p>ISO 21940-21:2012 specifies requirements for evaluating the performance of machines for balancing rotating components by the following tests: a) test for minimum achievable residual unbalance, <i>U</i>mar test; b) test for unbalance reduction ratio, URR test; c) test for couple unbalance interference on single-plane machines; d) compensator test.</p><p>These tests are performed du

## Source

- https://isopublicstorageprod.blob.core.windows.net/opendata/_latest/iso_deliverables_metadata/csv/iso_deliverables_metadata.csv

Last verified: 2026-08-05. Review by: 2027-02-01.
Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).