SIST EN ISO 4042:2018

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.

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oSIST prEN ISO 4042:2017

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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

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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
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copyright@iso.org
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© ISO 2017 – All rights reserved
iii
ii © ISO 2017 – All rights reserved

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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

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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

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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
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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
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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
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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
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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
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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
...