Fasteners - Electroplated coating systems (ISO 4042:2018)

This document specifies requirements for electroplated coatings and coating systems on steel
fasteners. The requirements related to dimensional properties also apply to fasteners made of copper
or copper alloys.
It also specifies requirements and gives recommendations to minimize the risk of hydrogen
embrittlement; see 4.4 and Annex B.
It mainly applies to zinc and zinc alloy coating systems (zinc, zinc-nickel, zinc-iron) and cadmium,
primarily intended for corrosion protection and other functional properties:
— with or without conversion coating;
— with or without sealant;
— with or without top coat;
— with or without lubricant (integral lubricant and/or subsequently added lubricant).
Specifications for other electroplated coatings and coating systems (tin, tin-zinc, copper-tin, coppersilver,
copper, silver, copper-zinc, nickel, nickel-chromium, copper-nickel, copper-nickel-chromium)
are included in this document only for dimensional requirements related to fasteners with ISO metric
threads.
This document applies to bolts, screws, studs and nuts with ISO metric thread, to fasteners with non-
ISO metric thread, and to non-threaded fasteners such as washers, pins, clips and rivets.
Information for design and assembly of coated fasteners is given in Annex A.
This document does not specify requirements for properties such as weldability or paintability.
NOTE Other International Standards specify differing electroplating processes. For electroplating of
fasteners, the requirements of this document apply, unless otherwise agreed.

Verbindungselemente - Galvanisch aufgebrachte Überzugsysteme (ISO 4042:2018)

Dieses Dokument legt Anforderungen an galvanisch aufgebrachte Überzüge und Überzugsysteme auf Ver-bindungselementen aus Stahl fest. Die Maßanforderungen gelten auch für Verbindungselemente aus Kupfer oder Kupferlegierungen.
Es legt außerdem Anforderungen fest und gibt Empfehlungen, um das Risiko der Wasserstoffversprödung zu minimieren; siehe 4.4 und Anhang B.
Es gilt hauptsächlich für Zink- und Zinklegierungsüberzugsysteme (Zink, Zink-Nickel, Zink-Eisen) und Cadmium, die vor allem für den Korrosionsschutz und weitere funktionelle Eigenschaften bestimmt sind:
- mit oder ohne Konversionsschicht;
- mit oder ohne Versiegelung;
- mit oder ohne Deckschicht;
- mit oder ohne Schmiermittel (integriertes Schmiermittel und/oder nachträglich aufgebrachtes Schmier-mittel).
Die Festlegungen für weitere galvanisch aufgebrachte Überzüge und Überzugsysteme (Zinn, Zinn-Zink, Kupfer-Zinn, Kupfer-Silber, Kupfer, Silber, Kupfer-Zink, Nickel, Nickel-Chrom, Kupfer-Nickel, Kupfer-Nickel-Chrom) sind in diesem Dokument nur für Maßanforderungen in Bezug auf Verbindungselemente mit metri-schem ISO-Gewinde enthalten.
Dieses Dokument gilt für Schrauben und Muttern mit metrischem ISO-Gewinde, für Verbindungselemente mit nicht metrischem ISO-Gewinde und für Verbindungselemente ohne Gewinde, wie Scheiben, Stifte, Clips und Niete.
Hinweise zur konstruktiven Ausführung und zur Montage von beschichteten Verbindungselementen sind in Anhang A aufgeführt.
Dieses Dokument legt keine Anforderungen an Eigenschaften wie Schweißbarkeit oder Lackierbarkeit fest.
ANMERKUNG Andere Internationale Normen legen abweichende Galvanikprozesse fest. Für das Aufbringen galvanischer Überzüge auf Verbindungselemente gelten die Anforderungen dieses Dokumentes, sofern nicht anders vereinbart.

Fixations - Systèmes de revêtements électrolytiques (ISO 4042:2018)

Le présent document spécifie les exigences applicables aux revêtements et aux systèmes de revêtement électrolytiques destinés aux fixations en acier. Les exigences portant sur les caractéristiques dimensionnelles s'appliquent également aux fixations en cuivre ou en alliages de cuivre.
Il spécifie également les exigences et donne des recommandations visant à réduire le risque de fragilisation par l'hydrogène; voir 4.4 et Annexe B.
Il s'applique principalement aux systèmes de revêtement de zinc et d'alliage de zinc (zinc, zinc-nickel, zinc-fer) et de cadmium, essentiellement destinés à la protection contre la corrosion et à l'obtention d'autres caractéristiques fonctionnelles:
—          avec ou sans couche de conversion;
—          avec ou sans finitions «sealer»;
—          avec ou sans finition «top coat»;
—          avec ou sans lubrifiant (lubrifiant intégré et/ou lubrifiant additionnel).
Les spécifications concernant d'autres revêtements et systèmes de revêtement électrolytiques (étain, étain-zinc, cuivre-étain, cuivre-argent, cuivre, argent, cuivre-zinc, nickel, nickel-chrome, cuivre-nickel, cuivre-nickel-chrome) sont incluses dans le présent document uniquement pour les exigences dimensionnelles relatives aux fixations à filetage métrique ISO.
Le présent document s'applique aux vis, goujons, tiges filetées et écrous à filetage métrique ISO, aux fixations à filetage non métrique ISO et aux fixations non filetées telles que les rondelles, les goupilles, les clips et les rivets.
Des informations sur la conception et l'assemblage des fixations revêtues sont données à l'Annexe A.
Le présent document ne spécifie pas d'exigence pour les caractéristiques telles que la soudabilité ou l'aptitude à la peinture.
NOTE       Des procédés de revêtement électrolytique différents sont spécifiés dans d'autres Normes internationales. Pour le revêtement électrolytique des fixations, les exigences du présent document s'appliquent, sauf accord contraire.

Mehanski vezni elementi - Sistemi galvanskih prevlek veznih elementov (ISO 4042:2018)

Ta dokument določa zahteve za galvanske prevleke veznih elementov in sisteme prevlek na mehanskih veznih elementih. Zahteve, povezane z dimenzijskimi lastnostmi, veljajo tudi za vezne elemente, izdelane iz bakra in bakrovih zlitin.
Določa tudi zahteve in podaja priporočila za zmanjševanje tveganja za krhkost v stiku z vodikom (glej 4.4. in dodatek B).
Uporablja se predvsem za sisteme cinkovih prevlek ter prevlek iz cinkovih zlitin (cink, cink-nikelj, cink-železo) in kadmija, namenjene predvsem za zaščito proti koroziji in zagotavljanje drugih funkcionalnih lastnosti:
– s konverzijskim premazom ali brez njega;
– s tesnilom ali brez njega;
– z vrhnjim premazom ali brez njega;
– z mazivom (integriranim ali naknadno dodanim) ali brez njega.
Specifikacije za druge galvanske prevleke in sisteme prevlek (kositer, kositer-cink, baker-kositer, baker-srebro, baker, srebro, baker-cink, nikelj, nikelj-krom, baker-nikelj, baker-nikelj-krom) so zajete v tem dokumentu samo za dimenzijske zahteve, povezane z veznimi elementi z ISO-metričnimi navoji.
Ta dokument se uporablja za vijake in matice z ISO-metričnim navojem, vezne elemente z metričnimi navoji, ki niso del ISO, ter vezne elemente brez navojev, kot so podložke, zatiči, objemke in zakovice.
Informacije o projektiranju in sestavljanju prevlečenih veznih elementov so podane v dodatku A. Ta dokument ne določa zahtev za lastnosti veznih elementov, kot je varivost ali možnost barvanja.
OPOMBA: Različne postopke galvanizacije določajo drugi mednarodni standardi. Če ni dogovorjeno drugače, za galvanizirane vezne elemente veljajo zahteve tega dokumenta.

General Information

Status
Withdrawn
Public Enquiry End Date
31-Jul-2017
Publication Date
02-Oct-2018
Withdrawal Date
22-Jun-2022
Technical Committee
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
22-Jun-2022
Due Date
15-Jul-2022
Completion Date
23-Jun-2022

Relations

Buy Standard

Standard
EN ISO 4042:2018 - BARVE
English language
65 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day
Draft
prEN ISO 4042:2017 - BARVE
English language
66 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 4042:2018
01-december-2018
1DGRPHãþD
SIST EN ISO 4042:2001
Mehanski vezni elementi - Sistemi galvanskih prevlek veznih elementov (ISO
4042:2018)
Fasteners - Electroplated coating systems (ISO 4042:2018)
Verbindungselemente - Galvanisch aufgebrachte Überzugsysteme (ISO 4042:2018)
Fixations - Systèmes de revêtements électrolytiques (ISO 4042:2018)
Ta slovenski standard je istoveten z: EN ISO 4042:2018
ICS:
21.060.01 Vezni elementi na splošno Fasteners in general
25.220.40 Kovinske prevleke Metallic coatings
SIST EN ISO 4042:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO 4042:2018

---------------------- Page: 2 ----------------------

SIST EN ISO 4042:2018


EN ISO 4042
EUROPEAN STANDARD

NORME EUROPÉENNE

September 2018
EUROPÄISCHE NORM
ICS 21.060.01 Supersedes EN ISO 4042:1999
English Version

Fasteners - Electroplated coating systems (ISO 4042:2018)
Fixations - Systèmes de revêtements électrolytiques Verbindungselemente - Galvanisch aufgebrachte
(ISO 4042:2018) Überzugsysteme (ISO 4042:2018)
This European Standard was approved by CEN on 4 July 2018.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4042:2018 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN ISO 4042:2018
EN ISO 4042:2018 (E)
Contents Page
European foreword . 3

2

---------------------- Page: 4 ----------------------

SIST EN ISO 4042:2018
EN ISO 4042:2018 (E)
European foreword
This document (EN ISO 4042:2018) has been prepared by Technical Committee ISO/TC 2 "Fasteners" in
collaboration with Technical Committee CEN/TC 185 “Fasteners” 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 March 2019, and conflicting national standards shall
be withdrawn at the latest by March 2019.
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 4042:1999.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 4042:2018 has been approved by CEN as EN ISO 4042:2018 without any modification.
3

---------------------- Page: 5 ----------------------

SIST EN ISO 4042:2018

---------------------- Page: 6 ----------------------

SIST EN ISO 4042:2018
INTERNATIONAL ISO
STANDARD 4042
Third edition
2018-08
Fasteners — Electroplated coating
systems
Fixations — Systèmes de revêtements électrolytiques
Reference number
ISO 4042:2018(E)
©
ISO 2018

---------------------- Page: 7 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2018
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
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

---------------------- Page: 8 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

Contents Page
Foreword .v
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 General characteristics of the coating . 3
4.1 Coating metals or alloys and main purposes . 3
4.2 Build-up of basic electroplated coating systems . 3
4.3 Coating systems and coating processes. 4
4.4 Internal hydrogen embrittlement. 4
4.4.1 General. 4
4.4.2 Fasteners with hardness below 360 HV . 5
4.4.3 Fasteners with hardness equal to and above 360 HV and up to 390 HV . 5
4.4.4 Fasteners with hardness above 390 HV . 5
4.4.5 Fasteners in accordance with ISO 898-1, ISO 898-2 and ISO 898-3 . 6
4.4.6 Baking and test requirements for case-hardened and tempered screws . 7
4.4.7 Work-hardened fasteners . 8
4.4.8 Fasteners with bainitic structure . 8
4.5 Baking . 8
5 Corrosion protection and testing . 8
5.1 General . 8
5.2 Neutral salt spray test (NSS) for zinc based coating systems . 9
5.3 Sulfur dioxide test (Kesternich test) .10
5.4 Bulk handling, automatic processes such as feeding and/or sorting, storage and
transport . .11
6 Dimensional requirements and testing .11
6.1 General .11
6.2 Fasteners with ISO metric thread .11
6.2.1 Coating thickness .11
6.2.2 Gaugeability and assemblability .12
6.3 Other fasteners .12
6.4 Test methods for thickness determination .13
7 Mechanical and physical properties and testing .15
7.1 General .15
7.2 Appearance .15
7.3 Corrosion resistance related to temperature .15
7.4 Torque/clamp force relationship .15
7.5 Determination of hexavalent chromium .15
8 Applicability of tests .15
8.1 General .15
8.2 Tests mandatory for each lot .15
8.3 Tests for in-process control.16
8.4 Tests to be performed when specified by the purchaser .16
9 Designation system .16
9.1 General .16
9.2 Designation of electroplated coating systems for the order .17
9.3 Examples of designation of hexavalent chromium free electroplated coating
systems for fasteners .18
9.4 Designation of fasteners with electroplated coating systems for labelling .19
10 Ordering requirements for electroplating .19
© ISO 2018 – All rights reserved iii

---------------------- Page: 9 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

11 Storage conditions .20
Annex A (informative) Design aspects and assembly of coated fasteners .21
Annex B (informative) Hydrogen embrittlement consideration .29
Annex C (informative) Corrosion protection related to zinc coatings with chromate
conversion coatings .33
Annex D (informative) Coating thickness and thread clearance for ISO metric screw threads .34
Annex E (informative) Coating systems tested in accordance with ISO 9227, NSS —
Evaluation of cabinet corrosivity for the neutral salt spray test .42
Annex F (informative) Obsolete designation codes for electroplated coating systems on
fasteners according to ISO 4042:1999 .51
Bibliography .54
iv © ISO 2018 – All rights reserved

---------------------- Page: 10 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 2, Fasteners, Subcommittee SC 14, Surface
coatings.
This third edition cancels and replaces the second edition (ISO 4042:1999), which has been technically
revised. The main changes compared to the previous edition are as follows:
— application to all fasteners, including self-tapping and thread forming screws, washers, rivets,
clips, etc.;
— focus on coatings designed for corrosion protection of fasteners;
— application to electroplated coating systems with or without additional layers (conversion coating,
sealant, top coat, lubricant);
— specification of minimum corrosion resistance (white corrosion and red rust);
— inclusion of up-to-date knowledge about hydrogen embrittlement and prevention measures;
— definitions specified in ISO 1891-2;
— concerning corrosion tests, inclusion of sulfur dioxide test (Kesternich) and calibration of neutral
salt spray test;
— inclusion of gaugeability and assemblability requirements;
— for thickness determination, addition of adequate test methods and deletion of the batch average
thickness;
— new designation system for all coating systems;
— specification for mechanical and physical properties and related test methods;
— information about design aspects and assembly of coated fasteners;
© ISO 2018 – All rights reserved v

---------------------- Page: 11 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

— information for coating thickness and thread clearance for ISO metric screw threads;
— information about evaluation of cabinet corrosivity for the neutral salt spray test.
vi © ISO 2018 – All rights reserved

---------------------- Page: 12 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

Introduction
This document was completely revised to take into account new developments related to hexavalent
chromium free passivations, application of sealants and top coats, requirements for functional
properties as well as results of research work to minimize the risk of hydrogen embrittlement.
© ISO 2018 – All rights reserved vii

---------------------- Page: 13 ----------------------

SIST EN ISO 4042:2018

---------------------- Page: 14 ----------------------

SIST EN ISO 4042:2018
INTERNATIONAL STANDARD ISO 4042:2018(E)
Fasteners — Electroplated coating systems
1 Scope
This document specifies requirements for electroplated coatings and coating systems on steel
fasteners. The requirements related to dimensional properties also apply to fasteners made of copper
or copper alloys.
It also specifies requirements and gives recommendations to minimize the risk of hydrogen
embrittlement; see 4.4 and Annex B.
It mainly applies to zinc and zinc alloy coating systems (zinc, zinc-nickel, zinc-iron) and cadmium,
primarily intended for corrosion protection and other functional properties:
— with or without conversion coating;
— with or without sealant;
— with or without top coat;
— with or without lubricant (integral lubricant and/or subsequently added lubricant).
Specifications for other electroplated coatings and coating systems (tin, tin-zinc, copper-tin, copper-
silver, copper, silver, copper-zinc, nickel, nickel-chromium, copper-nickel, copper-nickel-chromium)
are included in this document only for dimensional requirements related to fasteners with ISO metric
threads.
This document applies to bolts, screws, studs and nuts with ISO metric thread, to fasteners with non-
ISO metric thread, and to non-threaded fasteners such as washers, pins, clips and rivets.
Information for design and assembly of coated fasteners is given in Annex A.
This document does not specify requirements for properties such as weldability or paintability.
NOTE Other International Standards specify differing electroplating processes. For electroplating of
fasteners, the requirements of this document apply, unless otherwise agreed.
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 1456, Metallic and other inorganic coatings — Electrodeposited coatings of nickel, nickel plus
chromium, copper plus nickel and of copper plus nickel plus chromium
ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
ISO 1502, ISO general-purpose metric screw threads — Gauges and gauging
ISO 1891-2, Fasteners — Terminology — Part 2: Vocabulary and definitions for coatings
ISO 2081, Metallic and other inorganic coatings — Electroplated coatings of zinc with supplementary
treatments on iron or steel
ISO 2082, Metallic and other inorganic coatings — Electroplated coatings of cadmium with supplementary
treatments on iron or steel
© ISO 2018 – All rights reserved 1

---------------------- Page: 15 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

ISO 2093, Electroplated coatings of tin — Specification and test methods
ISO 2177, Metallic coatings — Measurement of coating thickness — Coulometric method by anodic
dissolution
ISO 2178, Non-magnetic coatings on magnetic substrates — Measurement of coating thickness —
Magnetic method
ISO 3231, Paints and varnishes — Determination of resistance to humid atmospheres containing sulfur dioxide
ISO 3497, Metallic coatings — Measurement of coating thickness — X-ray spectrometric methods
ISO 3613:2010, Metallic and other inorganic coatings — Chromate conversion coatings on zinc, cadmium,
aluminium-zinc alloys and zinc-aluminium alloys — Test methods
ISO 4521, Metallic and other inorganic coatings — Electrodeposited silver and silver alloy coatings for
engineering purposes — Specification and test methods
ISO 6988, Metallic and other non organic coatings — Sulfur dioxide test with general condensation of
moisture
ISO 8991, Designation system for fasteners
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 15330, Fasteners — Preloading test for the detection of hydrogen embrittlement — Parallel bearing
surface method
ISO 15726, Metallic and other inorganic coatings — Electrodeposited zinc alloys with nickel, cobalt or iron
ISO 16047, Fasteners — Torque/clamp force testing
ISO 16228, Fasteners — Types of inspection documents
ISO 19598, Metallic coatings — Electroplated coatings of zinc and zinc alloys on iron or steel with
supplementary Cr(VI)-free treatment
ISO 21968, Non-magnetic metallic coatings on metallic and non-metallic basis materials — Measurement
of coating thickness — Phase-sensitive eddy-current method
ASME B18.6.3, Machine Screws, Tapping Screws, and Metallic Drive Screws (Inch Series)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1891-2 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
reference panel
reference material that is to be exposed to check the corrosivity level of the test cabinet used for
fastener testing
2 © ISO 2018 – All rights reserved

---------------------- Page: 16 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

4 General characteristics of the coating
4.1 Coating metals or alloys and main purposes
Electroplated coating systems for steel fasteners are primarily applied for corrosion protection and
functional properties, such as torque/clamp force relationship.
In addition, other functional properties or decorative properties can be specified; see Annex A.
Table 1 shows commonly used electroplated coatings in relation with their main purposes and
references to related ISO standards, which give additional general information not covered by this
document, e.g. for designation. Some of the International Standards listed in Table 1 specify differing
electroplating processes. For the purpose of fasteners, the requirements of this document apply.
Table 1 — Electroplated coatings in accordance with their main purposes and related
ISO standards
Main purpose of
Coating metal(s) Nature the coating for ISO standard
fasteners
Symbol Element
Zn Zinc Metal P/D/F ISO 2081, ISO 19598
ZnNi Zinc-nickel Alloy P/D/F ISO 15726, ISO 19598
ZnFe Zinc-iron Alloy P/D/F ISO 15726, ISO 19598
a
Cd Cadmium Metal P/F ISO 2082
Ni Nickel Metal D/F ISO 1456
Ni+Cr Nickel-chromium Multi-layer D ISO 1456
Cu+Ni Copper-nickel Multi-layer D ISO 1456
Cu+Ni+Cr Copper-nickel-chromium Multi-layer D ISO 1456
CuZn Brass Alloy D —
CuSn Copper-tin (bronze) Alloy F —
Cu Copper Metal F/D —
Ag Silver Metal F/D ISO 4521
CuAg Copper-silver Alloy F —
Sn Tin Metal F ISO 2093
SnZn Tin-zinc Metal F/P —
P  corrosion protection
F  functional properties
D decorative properties (colour, aspect)
a
Cadmium is restricted or prohibited for many applications (remaining cadmium users are predominantly military and
aerospace industries).
4.2 Build-up of basic electroplated coating systems
Figure 1 shows basic electroplated coating systems.
© ISO 2018 – All rights reserved 3

---------------------- Page: 17 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

Key
1 only metal layer(s)
2 metal layer(s) + conversion coating
3 metal layer(s) + conversion coating + additional lubricant
4 metal layer(s) + conversion coating + sealant/top coat
5 metal layer(s) + conversion coating + sealant/top coat + additional lubricant
Figure 1 — Basic electroplated coating systems (schematic)
A conversion coating increases corrosion protection on zinc, zinc alloys and cadmium coatings. It may
be a passivation (chromium VI free) or a chromatation (chromium VI containing). The conversion
coating can also provide better adhesion for additional layer(s) and/or additional colour/paint.
An additional sealant/top coat (with or without integral lubricant) may be chosen to increase corrosion
resistance and to achieve other specific properties (e.g. torque/clamp force properties, resistance to
chemicals, mechanical resistance, aspect, colour, thermal stability, increased electrical resistance, UV
radiation resistance). The selection of the nature of a sealant or top coat should be based on desired
additional properties.
An additional lubricant may be applied to adjust or amend the torque/clamp force relationship.
4.3 Coating systems and coating processes
The type and geometry of the fasteners should be considered when selecting a coating system and the
related coating process (see Annex A) as well as hydrogen embrittlement considerations (see Annex B).
The electroplating process shall be under control, in accordance with a recognized standard and/or a
specification by agreement with the customer.
4.4 Internal hydrogen embrittlement
4.4.1 General
If the three following conditions are concurrently present for fasteners:
— with high tensile strength or hardness or which have been case-hardened and tempered or cold
worked to high hardness,
— which are under tensile stress, and
— which have absorbed hydrogen,
there is a risk of Internal Hydrogen Embrittlement (IHE).
The susceptibility to IHE increases with increasing hardness of the fastener material. Appropriate
measures for prevention of IHE for quenched and tempered fasteners depending on hardness are
4 © ISO 2018 – All rights reserved

---------------------- Page: 18 ----------------------

SIST EN ISO 4042:2018
ISO 4042:2018(E)

specified in Table 2. For fasteners in accorda
...

SLOVENSKI STANDARD
oSIST prEN ISO 4042:2017
01-julij-2017
Mehanski vezni elementi - Sistemi galvanskih prevlek veznih elementov (ISO/DIS
4042:2017)
Fasteners - Electroplated coating systems (ISO/DIS 4042:2017)
Verbindungselemente - Galvanisch aufgebrachte Überzugsysteme (ISO/DIS 4042:2017)
Fixations - Systèmes de revêtements électrolytiques (ISO/DIS 4042:2017)
Ta slovenski standard je istoveten z: prEN ISO 4042
ICS:
21.060.01 Vezni elementi na splošno Fasteners in general
25.220.40 Kovinske prevleke Metallic coatings
oSIST prEN ISO 4042:2017 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO 4042:2017

---------------------- Page: 2 ----------------------
oSIST prEN ISO 4042:2017
DRAFT INTERNATIONAL STANDARD
ISO/DIS 4042
ISO/TC 2/SC 14 Secretariat: DIN
Voting begins on: Voting terminates on:
2017-06-01 2017-08-23
Fasteners — Electroplated coating
systems
Fixations — Systèmes de revêtements électrolytiques
ICS: 21.060.01
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 4042:2017(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2017

---------------------- Page: 3 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E) ISO/DIS 4042:2017(E)

Contents Page
Foreword . iv
Introduction . vi
1 Scope .1
2 Normative references .2
3 Terms and definitions .3
4 General characteristics of the coating .4
5 Corrosion protection and testing . 10
6 Dimensional requirements and testing . 13
7 Mechanical and physical properties and testing . 18
8 Applicability of tests . 19
9 Designation system . 19
10 Ordering requirements for electroplating . 24
11 Storage conditions . 24
Annex A (informative) Design aspects and assembly of coated fasteners . 25
Annex B (informative) Hydrogen embrittlement consideration . 33
Annex C (informative) Corrosion protection related to chromate conversion coatings . 38
Annex D (informative) Coating thickness and thread clearance for ISO metric screw
threads . 39
Annex E (informative) Coating systems tested in accordance with ISO 9227, NSS —
Evaluation of cabinet corrosivity for the neutral salt spray test . 47
E.1 Introduction. 47
E.2 Purpose . 47
E.3 Frequency of controls . 47
E.4 Operating conditions . 47
E.5 Corrosivity results . 53
Annex F (informative) Obsolete designation codes for electroplated coatings on fasteners
according to ISO 4042:1999 . 57
COPYRIGHT PROTECTED DOCUMENT
Bibliography . 60
© ISO 2017, Published in Switzerland

All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
© ISO 2017 – All rights reserved
iii
ii © ISO 2017 – All rights reserved

---------------------- Page: 4 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E)
Contents Page
Foreword . iv
Introduction . vi
1 Scope .1
2 Normative references .2
3 Terms and definitions .3
4 General characteristics of the coating .4
5 Corrosion protection and testing . 10
6 Dimensional requirements and testing . 13
7 Mechanical and physical properties and testing . 18
8 Applicability of tests . 19
9 Designation system . 19
10 Ordering requirements for electroplating . 24
11 Storage conditions . 24
Annex A (informative) Design aspects and assembly of coated fasteners . 25
Annex B (informative) Hydrogen embrittlement consideration . 33
Annex C (informative) Corrosion protection related to chromate conversion coatings . 38
Annex D (informative) Coating thickness and thread clearance for ISO metric screw
threads . 39
Annex E (informative) Coating systems tested in accordance with ISO 9227, NSS —
Evaluation of cabinet corrosivity for the neutral salt spray test . 47
E.1 Introduction. 47
E.2 Purpose . 47
E.3 Frequency of controls . 47
E.4 Operating conditions . 47
E.5 Corrosivity results . 53
Annex F (informative) Obsolete designation codes for electroplated coatings on fasteners
according to ISO 4042:1999 . 57
Bibliography . 60


© ISO 2017 – All rights reserved
iii

---------------------- Page: 5 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E)
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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following URL:
www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 2/SC 14, Surface coatings.
This second edition cancels and replaces the first edition (ISO 4042:1999) completely. The main
technical changes are the following:
— application to all fasteners, including self-tapping and thread forming screws, washers, rivets, clips,
etc.,
— focus on coatings designed for corrosion protection of fasteners,
— application to electroplated coatings with or without additional layers (conversion coating, sealant,
top coat, lubricant),
— specification of minimum corrosion resistance (white corrosion and red rust),
— inclusion of up-to-date knowledge about hydrogen embrittlement and prevention measures,
— definitions specified in separate standard ISO 1891-2,
— concerning corrosion tests, inclusion of sulfur dioxide test (Kesternich) and calibration of neutral
salt spray test (NSS),
© ISO 2017 – All rights reserved
iv

---------------------- Page: 6 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E) ISO/DIS 4042:2017(E)
— inclusion of gaugeability and assemblability requirements,
— for thickness determination, addition of adequate test methods and deletion of the batch average
Foreword
thickness,
— new designation system for all coating systems
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
— specification for mechanical and physical properties and related test methods,
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.
— information about design aspects and assembly of coated fasteners
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
— information for coating thickness and thread clearance for ISO metric screw threads
matters of electrotechnical standardization.
— information about evaluation of cabinet corrosivity for the neutral salt spray test
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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on 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 the following URL:
www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 2/SC 14, Surface coatings.
This second edition cancels and replaces the first edition (ISO 4042:1999) completely. The main
technical changes are the following:
— application to all fasteners, including self-tapping and thread forming screws, washers, rivets, clips,
etc.,
— focus on coatings designed for corrosion protection of fasteners,
— application to electroplated coatings with or without additional layers (conversion coating, sealant,
top coat, lubricant),
— specification of minimum corrosion resistance (white corrosion and red rust),
— inclusion of up-to-date knowledge about hydrogen embrittlement and prevention measures,
— definitions specified in separate standard ISO 1891-2,
— concerning corrosion tests, inclusion of sulfur dioxide test (Kesternich) and calibration of neutral
salt spray test (NSS),
© ISO 2017 – All rights reserved © ISO 2017 – All rights reserved
iv v

---------------------- Page: 7 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E)
Introduction
The revision of this International Standard takes into account new developments related to hexavalent
chromium free passivations, application of sealants and top coats, requirements for functional
properties as well as results of research work to minimize the risk of hydrogen embrittlement.
Consequently, this standard was completely revised.
© ISO 2017 – All rights reserved
vi

---------------------- Page: 8 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E)
DRAFT INTERNATIONAL STANDARD ISO/DIS 4042:2017(E)

Introduction
Fasteners — Electroplated coating systems
The revision of this International Standard takes into account new developments related to hexavalent
chromium free passivations, application of sealants and top coats, requirements for functional
properties as well as results of research work to minimize the risk of hydrogen embrittlement.
1 Scope
Consequently, this standard was completely revised.
This International Standard specifies requirements for electroplated coatings and coating systems on
steel fasteners. The requirements related to dimensional properties also apply to fasteners made of
copper or copper alloys.
This International Standard also specifies requirements and gives recommendations to minimize the
risk of hydrogen embrittlement, see 4.4 and Annex B.
This International Standard mainly applies to zinc and zinc alloy coating systems (zinc, zinc-iron, zinc-
nickel) and cadmium, primarily intended for corrosion protection and other functional properties:
— with or without conversion coating;
— with or without sealant;
— with or without top coat;
— with or without lubricant (integral lubricant and/or subsequently added lubricant).
Specifications for other electroplated coatings and coating systems (tin, tin-zinc, copper-tin, copper-
silver, copper, silver, copper-zinc, nickel, nickel-chromium, copper-nickel, copper-nickel-chromium) are
included in this standard only for dimensional requirements related to fasteners with ISO metric
threads.
National regulations for the restriction or prohibition of certain chemical elements and compounds
shall be taken into account in the countries or regions concerned.
Although other ISO standards specify various electroplating processes, the requirements of this
International Standard supersede other ISO standards for electroplating of fasteners, unless otherwise
agreed at the time of the order.
This International Standard applies to bolts, screws, studs and nuts with ISO metric thread, to fasteners
with non-ISO metric thread, and to non-threaded fasteners such as washers, pins, clips and rivets.
Information for design and assembly of coated fasteners is given in Annex A.
This International Standard does not specify requirements for properties such as weldability or
paintability.
© ISO 2017 – All rights reserved
© ISO 2017 – All rights reserved
vi 1

---------------------- Page: 9 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E)
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 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws
and studs with specified property classes — Coarse thread and fine pitch thread
ISO 898-2, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 2: Nuts with
specified property classes — Coarse thread and fine pitch thread
ISO/DIS 898-3, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 3: Washers
ISO 898-5, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 5: Set screws
and similar threaded fasteners with specified hardness classes — Coarse thread and fine pitch thread
ISO 965-1, ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data
ISO 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general
purpose external and internal screw threads — Medium quality
ISO 965-3, ISO general purpose metric screw threads — Tolerances — Part 3: Deviations for
constructional screw threads
ISO 10666, Drilling screws with tapping screw thread — Mechanical and functional properties
ISO 1456, Metallic and other inorganic coatings — Electrodeposited coatings of nickel, nickel plus
chromium, copper plus nickel and of copper plus nickel plus chromium
ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
ISO 1502, ISO general-purpose metric screw threads — Gauges and gauging
ISO 2081, Metallic and other inorganic coatings — Electroplated coatings of zinc with supplementary
treatments on iron or steel
ISO 2082, Metallic and other inorganic coatings — Electroplated coatings of cadmium with
supplementary treatments on iron or steel
ISO 2093, Electroplated coatings of tin — Specification and test methods
ISO 2177, Metallic coatings — Measurement of coating thickness — Coulometric method by anodic
dissolution
ISO 2178, Non-magnetic coatings on magnetic substrates — Measurement of coating thickness —
Magnetic method
ISO 2702, Heat-treated steel tapping screws — Mechanical properties
ISO 3231, Paints and varnishes — Determination of resistance to humid atmospheres containing sulfur
dioxide
ISO 3497, Metallic coatings — Measurement of coating thickness — X-ray spectrometric methods
© ISO 2017 – All rights reserved
2

---------------------- Page: 10 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E) ISO/DIS 4042:2017(E)
2 Normative references
ISO 3613:2010, Metallic and other inorganic coatings — Chromate conversion coatings on zinc, cadmium,
aluminium-zinc alloys and zinc-aluminium alloys — Test methods
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
ISO 4521, Metallic and other inorganic coatings — Electrodeposited silver and silver alloy coatings for
undated references, the latest edition of the referenced document (including any amendments) applies.
engineering purposes — Specification and test methods
ISO 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts, screws
ISO 6988, Metallic and other non organic coatings — Sulfur dioxide test with general condensation of
and studs with specified property classes — Coarse thread and fine pitch thread
moisture
ISO 898-2, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 2: Nuts with
ISO 7085, Mechanische und funktionelle Anforderungen von einsatzgehärteten und angelassenen
specified property classes — Coarse thread and fine pitch thread
metrischen gewindefurchenden Schrauben (withdrawn)
ISO/DIS 898-3, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 3: Washers
ISO 8991, Designation system for fasteners
ISO 898-5, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 5: Set screws
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
and similar threaded fasteners with specified hardness classes — Coarse thread and fine pitch thread
ISO 15726, Metallic and other inorganic coatings — Electrodeposited zinc alloys with nickel, cobalt or iron
ISO 965-1, ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data
ISO 16047, Fasteners — Torque/clamp force testing
ISO 965-2, ISO general purpose metric screw threads — Tolerances — Part 2: Limits of sizes for general
purpose external and internal screw threads — Medium quality
ISO 16228, Fasteners — Inspection documents
ISO 965-3, ISO general purpose metric screw threads — Tolerances — Part 3: Deviations for
ISO 19598, Metallic coatings — Electroplated coatings of zinc and zinc alloys on iron or steel with
constructional screw threads
supplementary Cr(VI)-free treatment
ISO 10666, Drilling screws with tapping screw thread — Mechanical and functional properties
ISO 21968, Non-magnetic metallic coatings on metallic and non-metallic basis materials — Measurement
of coating thickness — Phase-sensitive eddy-current method
ISO 1456, Metallic and other inorganic coatings — Electrodeposited coatings of nickel, nickel plus
chromium, copper plus nickel and of copper plus nickel plus chromium
ASME B18.6.3, Machine Screws, Tapping Screws, and Metallic Drive Screws (Inch Series)
ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
ASTM F1940, Standard Test Method for Process Control Verification to Prevent Hydrogen Embrittlement
in Plated or Coated Fasteners
ISO 1502, ISO general-purpose metric screw threads — Gauges and gauging
DIN 50969-2, Prevention of hydrogen-induced brittle fracture of high-strength steel building elements —
ISO 2081, Metallic and other inorganic coatings — Electroplated coatings of zinc with supplementary
Part 2: Test methods
treatments on iron or steel
3 Terms and definitions
ISO 2082, Metallic and other inorganic coatings — Electroplated coatings of cadmium with
supplementary treatments on iron or steel
For the purposes of this document, the terms and definitions given in ISO 1891-2 and the following apply.
ISO 2093, Electroplated coatings of tin — Specification and test methods
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
ISO 2177, Metallic coatings — Measurement of coating thickness — Coulometric method by anodic
— IEC Electropedia: available at http://www.electropedia.org/
dissolution
— ISO Online browsing platform: available at http://www.iso.org/obp
ISO 2178, Non-magnetic coatings on magnetic substrates — Measurement of coating thickness —
Magnetic method
3.1
reference panel
ISO 2702, Heat-treated steel tapping screws — Mechanical properties
reference material that is to be exposed to check the corrosivity level of the test cabinet used for
ISO 3231, Paints and varnishes — Determination of resistance to humid atmospheres containing sulfur fastener testing
dioxide
ISO 3497, Metallic coatings — Measurement of coating thickness — X-ray spectrometric methods
© ISO 2017 – All rights reserved © ISO 2017 – All rights reserved
2 3

---------------------- Page: 11 ----------------------
oSIST prEN ISO 4042:2017
ISO/DIS 4042:2017(E)
4 General characteristics of the coating
4.1 Coating metals or alloys and main purposes
Electroplated coating systems for steel fasteners are primarily applied for corrosion protection and
functional properties, such as torque/clamp force relationship.
In addition, other functional properties or decorative properties can be specified, see Annex A.
Table 1 shows commonly used electroplated coatings in relation with their main purposes and
references to related ISO standards, which give additional general information not covered by this
International Standard, e.g. for designation. The requirements of this standard supersede the
specifications of ISO standards listed in Table 1 for the purpose of fasteners.
Table 1 — Electroplated coatings in accordance with their main purposes and related
ISO standards
Coating metal(s) Main purpose
Nature of the coating ISO standard
Symbol Element
for fasteners
Zn Zinc Metal P / D / F ISO 2081, ISO 19598
ZnNi Zinc-nickel Alloy P / D / F ISO 15726, ISO 19598
ZnFe Zinc-iron Alloy P / D / F ISO 15726, ISO 19598
a
Cd Metal P / F ISO 2082
Cadmium
Ni Nickel Metal D ISO 1456
Ni+Cr Nickel-chromium Multi-layer D ISO 1456
Cu+Ni Copper-nickel Multi-layer D ISO 1456
Cu+Ni+Cr Copper-nickel-chromium Multi-layer D ISO 1456
CuZn Brass Alloy D —
CuSn Copper-tin (bronze) Alloy F —
Cu Copper Metal F / D —
Ag Silver Metal F / D ISO 4521
CuAg Copper-silver Alloy F —
Sn Tin Metal F ISO 2093
SnZn Tin-zinc Metal F / P —
P Corrosion Protection
F Functional properties
D Decorative properties (colour, aspect)
a
Cadmium is restricted or prohibited for many applications (remaining cadmium users are predominantly milita
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.