SIST EN ISO 2081:2026

SLOVENSKI STANDARD
01-januar-2026
Kovinske in druge anorganske prevleke - Galvanske prevleke na železu in jeklu z
uporabo cinka, obdelanega z raztopinami, ki vsebujejo krom (VI) (ISO 2081:2025)
Metallic and other inorganic coatings - Electroplated coatings on iron and steel using zinc
treated with solutions containing chromium (VI) (ISO 2081:2025)
Metallische und andere anorganische Überzüge- Mit Chrom(VI)-haltigen Lösungen
behandelte galvanische Überzüge auf Eisen und Stahl unter Verwendung von Zink (ISO
2081:2025)
Revêtements métalliques et autres revêtements inorganiques - Dépôts électrolytiques de
zinc traité par des solutions contenant du chrome (VI) sur fer ou acier (ISO 2081:2025)
Ta slovenski standard je istoveten z: EN ISO 2081:2025
ICS:
25.220.40 Kovinske prevleke Metallic coatings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 2081
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2025
EUROPÄISCHE NORM
ICS 25.220.40 Supersedes EN ISO 2081:2018
English Version
Metallic and other inorganic coatings - Electroplated
coatings on iron and steel using zinc treated with solutions
containing chromium (VI) (ISO 2081:2025)
Revêtements métalliques et autres revêtements Metallische und andere anorganische Überzüge- Mit
inorganiques - Dépôts électrolytiques de zinc traité par Chrom(VI)-haltigen Lösungen behandelte galvanische
des solutions contenant du chrome (VI) sur fer ou acier Überzüge auf Eisen und Stahl unter Verwendung von
(ISO 2081:2025) Zink (ISO 2081:2025)
This European Standard was approved by CEN on 18 October 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 2081:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 2081:2025) has been prepared by Technical Committee ISO/TC 107 "Metallic
and other inorganic coatings" in collaboration with Technical Committee CEN/TC 262 “Metallic and
other inorganic coatings, including for corrosion protection and corrosion testing of metals and alloys”
the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2026, and conflicting national standards shall be
withdrawn at the latest by May 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 2081:2018.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 2081:2025 has been approved by CEN as EN ISO 2081:2025 without any modification.

International
Standard
ISO 2081
Fifth edition
Metallic and other inorganic
2025-11
coatings — Electroplated coatings on
iron and steel using zinc treated with
solutions containing chromium (VI)
Revêtements métalliques et autres revêtements inorganiques —
Dépôts électrolytiques de zinc traité par des solutions contenant
du chrome (VI) sur fer ou acier
Reference number
ISO 2081:2025(en) © ISO 2025
ISO 2081:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 2081:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, abbreviated terms and symbols . 2
3.1 Terms and definitions .2
3.2 Abbreviated terms .2
3.3 Symbols .2
4 Information to be supplied by the purchaser to the electroplater . 3
4.1 Essential information .3
4.2 Additional information.3
5 Designation . 3
5.1 General .3
5.2 Designation specification.4
5.3 Designation of the basis material .4
5.4 Designation of heat treatment requirements .5
6 Requirements . 5
6.1 Appearance .5
6.2 Thickness .5
6.3 Conversion coatings and other supplementary treatments .5
6.4 Adhesion of zinc and conversion coatings .6
6.5 Accelerated corrosion testing .6
6.5.1 Neutral salt spray test .6
6.5.2 Corrosion rating .7
6.6 Stress relief heat treatments before cleaning and electroplating .7
6.7 Hydrogen-embrittlement-relief heat treatments after electroplating .7
7 Sampling . 7
Annex A (normative) Designation of supplementary treatments . 9
Annex B (normative) Measurement of average thickness of coating on small articles .11
Bibliography .12

iii
ISO 2081:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by ISO Technical Committee TC 107, Metallic and other inorganic coatings,
Subcommittee SC 3, Electrodeposited coatings and related finishes, in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 262, Metallic and other inorganic
coatings, including for corrosion protection and corrosion testing of metals and alloys, in accordance with the
agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This fifth edition cancels and replaces the fourth edition (ISO 2081:2018), which has been technically
revised.
The main changes are as follows:
— Table 2 has been added.
— References to trivalent chromium [Cr (III)] passivate have been removed, as these systems are addressed
in ISO 19598.
— References to sampling have been updated to reflect actual industry practice.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO 2081:2025(en)
Introduction
Zinc coatings are applied to iron or steel articles for protective and decorative purposes by electrodeposition
from acid zinc chloride, alkaline non-cyanide zinc and alkaline zinc cyanide solutions. Electroplated, bright
zinc coatings are popular and the processes for preparing bright zinc coatings are widely used.
The ability of a zinc coating to prevent corrosion is a function of its thickness and the type of service
conditions to which it is exposed. For example, the rate of corrosion of zinc is generally greater in industrial
atmospheres than in rural ones. The type of service condition should, therefore, be taken into consideration
when specifying the minimum coating thickness. Chromate conversion coatings and other supplementary
treatments enhance the corrosion resistance of electrodeposited zinc coatings and are commonly applied
after electroplating.
Because the appearance and serviceability of zinc coatings depends on the surface condition of the basis
metal, agreement should be reached between the interested parties that the surface finish of the basis metal
is satisfactory for electroplating.
Chromium (VI) conversion coatings are omitted or replaced by other conversion coatings at the specific
request of the purchaser. This document provides the codes for all types of chromium (VI) conversion and
other supplementary coatings.
With reference to chromium (VI)-free conversion coatings, attention is drawn to ISO 19598. ISO 19598 is
applicable to zinc, zinc-iron and zinc-nickel plating, where only trivalent systems are required.
Due to the REACH Regulations, the use of hexavalent chromium compounds was banned in Europe except
where specifically authorized in September 2017. Alternative conversion coatings or substitutes can be used
where required to satisfy the corrosion requirements given in this document.

v
International Standard ISO 2081:2025(en)
Metallic and other inorganic coatings — Electroplated
coatings on iron and steel using zinc treated with solutions
containing chromium (VI)
WARNING — This document calls for the use of substances or procedures, or both, that can be
injurious to health if adequate safety measures are not taken. This document does not address any
health hazards, safety or environmental matters associated with its use. It is the responsibility of
the producers, purchasers and users of this document to establish appropriate health, safety and
environmentally acceptable practices.
1 Scope
This document specifies requirements for electroplated coatings of zinc with supplementary treatments
using hexavalent chromium compounds on iron or steel. It includes information to be supplied by the
purchaser to the electroplater, and the requirements for heat treatment before and after electroplating.
This document is not applicable to zinc coatings applied:
— to sheet, strip or wire in the non-fabricated form;
— to close-coiled springs;
— for purposes other than protective and decorative.
This document does not specify requirements for the surface condition of the basis metal prior to
electroplating with zinc. However, defects in the surface of the basis metal can adversely affect the
appearance and performance of the coating.
The coating thickness that can be applied to threaded components can be limited by dimensional
requirements, including class or fit.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
ISO 2064, Metallic and other inorganic coatings — Definitions and conventions concerning the measurement of
thickness
ISO 2080, Metallic and other inorganic coatings — Surface treatment, metallic and other inorganic coating —
Vocabulary
ISO 2177, Metallic coatings — Measurement of coating thickness — Coulometric method by anodic dissolution
ISO 2819, Metallic coatings on metallic substrates — Electrodeposited and chemically deposited coatings —
Review of methods available for testing adhesion
ISO 3613, Metallic and other inorganic coatings — Chromate conversion coatings on zinc, cadmium, aluminium-
zinc alloys and zinc-aluminium alloys — Test methods

ISO 2081:2025(en)
ISO 4519, Electrodeposited metallic coatings and related finishes — Sampling procedures for inspection by
attributes
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 24251-1, Prevention of hydrogen assisted brittle fracture of high-strength steel components — Part 1:
Fundamentals and measures
ISO 10289, Methods for corrosion testing of metallic and other inorganic coatings on metallic substrates —
Rating of test specimens and manufactured articles subjected to corrosion tests
ISO 10587, Metallic and other inorganic coatings — Test for residual embrittlement in both metallic-coated and
uncoated externally-threaded articles and rods — Inclined wedge method
ISO 15330, Fasteners — Preloading test for the detection of hydrogen embrittlement — Parallel bearing
surface method
ISO 15724, Metallic and other inorganic coatings — Electrochemical measurement of diffusible hydrogen in
steels — Barnacle electrode method
3 Terms, definitions, abbreviated terms and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2064 and ISO 2080 apply.
ISO and IEC maintain terminology databases for
...