ISO 6621-4:2015

Internal combustion engines — Piston rings — Part 4: General specifications

ISO 6621-4:2015 specifies the general characteristics of piston rings for reciprocating internal combustion engines for road vehicles and other applications (the individual dimensional criteria for these rings are given in the relevant International Standards). It also provides a system for ring coding, designation, and marking. It is applicable to all such rings of a nominal diameter from 30 mm up to and including 200 mm.

Moteurs à combustion interne — Segments de piston — Partie 4: Spécifications générales

General Information

• Status: Withdrawn
• Publication Date: 17-Mar-2015
• ICS: 43.060.10 - Engine block and internal components
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34/WG 4 - Piston rings
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 01-May-2024

Relations

• Revised: ISO 6621-4:2024 - Internal combustion engines — Piston rings — Part 4: General specifications
• Effective Date: 04-Sep-2021
• Revises: ISO 6621-4:2003 - Internal combustion engines — Piston rings — Part 4: General specifications
• Effective Date: 29-Jan-2011

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 6621-4
Third edition
2015-03-15
Internal combustion engines — Piston
rings —
Part 4:
General specifications
Moteurs à combustion interne — Segments de piston —
Partie 4: Spécifications générales
Reference number
ISO 6621-4:2015(E)
©
ISO 2015

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ISO 6621-4:2015(E)

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ii © ISO 2015 – All rights reserved

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ISO 6621-4:2015(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Piston ring codes . 1
5 Designation of piston rings . 4
5.1 Designation elements and order . 4
5.2 Designation examples . 5
6 Marking of piston rings . 6
6.1 General . 6
6.2 Mandatory topside identification marking . 6
6.3 Additional marking . 7
7 General characteristics . 7
7.1 Ring shape . 7
7.2 Light tightness . 8
7.3 Closed gap . 8
7.4 Tangential force, F , and diametral force, F , of single piece piston rings . 8
t d
7.5 Tangential force F of multipiece oil control rings as specified in ISO 6626-1, ISO 6626-2,
t
and ISO 6626-3 .
...