# ISO 6621-4:1988 — Withdrawn and superseded ISO standards

For ISO 6621-4:1988, item title is Internal combustion engines — Piston rings — Part 4: General specifications; status code is 9599; successor is ISO 6621-4:2003; withdrawn / published date is 1988-12-29, recorded from its source on 2026-08-05.

- **Identifier:** ISO 6621-4:1988 _(verified: appears in the quote below)_
- **Item title:** Internal combustion engines — Piston rings — Part 4: General specifications _(verified: appears in the quote below)_
- **Status code:** 9599 _(verified: appears in the quote below)_
- **Successor:** ISO 6621-4:2003
- **Withdrawn / published date:** 1988-12-29 _(verified: appears in the quote below)_

## What the source says

> 13036,IS,,ISO 6621-4:1988,Internal combustion engines — Piston rings — Part 4: General specifications,Moteurs à combustion interne — Segments de piston — Partie 4: Spécifications générales,1988-12-29,1,['43.060.10'],ISO/TC 22,9599,,[38306],"['en','fr']",13,"<p>This part lays down the general characteristics of piston rings, individual dimensional criteria of which are specified as appropriate in the ISO publications cited in clause 0. Provides a system for coding, designation and marking of the piston rings. Applies to all rings up to and including 200 mm diameter covered by the above classification for both reciprocating internal combustion piston engines and compressors.</p>"

## 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Part of [Withdrawn and superseded ISO standards](https://referencesource.org/iso-standard-supersessions/).