SIST EN ISO 26945:2011

• Abstract:

  ISO 26945:2011 specifies electrodeposited coatings of tin-cobalt alloy of approximate composition 75 % (mass fraction) to 80 % (mass fraction) tin, remainder cobalt, as a substitute for decorative chromium coatings of 0,1 µm to 0,3 µm thickness. Hardness and wear resistance properties of the coatings obtained are not equivalent to those of chromium coatings, but similar to those of tin-nickel alloy coatings.; Tin-cobalt alloy coatings can be applied by rack or barrel plating processes.; ISO 26945:2011 does not specify requirements for the surface condition of the basis metal prior to electroplating.

• Status: Published
• Publication Date: 10-Oct-2011
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: IPKZ - Protection of metals against corrosion
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 21-Sep-2011
• Due Date: 26-Nov-2011
• Completion Date: 11-Oct-2011
• Ref Project: EN ISO 26945:2011 - Metallic and other inorganic coatings - Electrodeposited coatings of tin-cobalt alloy (ISO 26945:2011)

• Replaces: SIST EN ISO 26945:2009 - Metallic and other inorganic coatings - Electrodeposited coatings of tin-cobalt alloy (ISO 26945:2008)
• Effective Date: 01-Nov-2011
• Refers: SIST ISO 4519:1999 - Electrodeposited metallic coatings and related finishes -- Sampling procedures for inspection by attributes
• Effective Date: 25-Aug-2026
• Refers: SIST ISO 2064:1999 - Metallic and other inorganic coatings -- Definitions and conventions concerning the measurement of thickness
• Effective Date: 25-Aug-2026
• Refers: SIST EN 4495:2009 - Aerospace series - Bolts, normal hexagonal head, close tolerance normal shank, short thread, in titanium alloy, anodized, with aluminium pigmented coating, metric series - Classification: 1 100 MPa (at ambient temperature) / 315 °C
• Effective Date: 28-Jan-2026
• Refers: SIST EN ISO 21258:2010 - Stationary source emissions - Determination of the mass concentration of dinitrogen monoxide (N2O) - Reference method: Non-dispersive infrared method (ISO 21258:2010)
• Effective Date: 28-Jan-2026
• Refers: SIST EN 12764:2005 - Sanitary appliances - Specification for whirlpool baths
• Effective Date: 28-Jan-2026
• Refers: SIST EN 46002:1999 - Quality systems - Medical devices - Particular requirements for the application of EN ISO 9002
• Effective Date: 28-Jan-2026
• Refers: SIST EN 3084:2002 - Aerospace series - Pipe coupling 8°30' in titanium alloy - Unions, welded end threaded for repair
• Effective Date: 28-Jan-2026
• Refers: SIST EN 23923-1:2000 - Metallic powders - Determination of apparent density - Part 1: Funnel method (ISO 3923-1:1979)
• Effective Date: 28-Jan-2026
• Refers: SIST EN 12249:2003 - Sawn timber used in pallets - Permitted deviations and guidelines for dimensions
• Effective Date: 28-Jan-2026

SIST EN ISO 26945:2011 is the Slovenian adoption of EN ISO 26945:2011 for electrodeposited coatings of tin-cobalt alloy. The standard specifies coatings of about 75% to 80% tin, with cobalt as the balance, as an alternative to decorative chromium coatings of 0.1 µm to 0.3 µm thickness. It is written for purchasers, electroplating processors and inspectors who need to specify the coating, check thickness and adhesion, and manage heat treatment and sampling.

What does SIST EN ISO 26945:2011 specify?

SIST EN ISO 26945:2011 covers electrodeposited tin-cobalt alloy coatings on metal parts, including coatings applied by rack or barrel plating. It sets out how to specify the coating, what information the purchaser must provide, the main performance and inspection requirements, and how to measure thickness and sample lots.

The standard does not set the surface condition of the basis metal before electroplating. In practice, that means the purchaser and processor need to agree on the starting finish and any pretreatment before work begins.

Annex	What it covers
A	Methods for measuring the thickness of tin-cobalt alloy coatings and the content of the thickness test report

The document is organized into clauses on scope, references, terms, purchaser information, designation, requirements and sampling, followed by Annex A for thickness measurement.

What are the key requirements of SIST EN ISO 26945:2011?

Coating system and basis material

SIST EN ISO 26945:2011 is intended for tin-cobalt alloy coatings used in place of decorative chromium coatings. The coatings are similar in brightness to chromium, but their hardness and wear resistance are not equivalent to chromium and are closer to tin-nickel alloy coatings. For buyers, that means the coating is chosen mainly for appearance and decorative service, not as a direct substitute for chromium in wear performance.

Clause 6.1 addresses basis material preparation. Some substrates, such as phosphor-bronze, beryllium-copper and nickel-iron alloys, may need a copper undercoat because they are difficult to prepare chemically clean. Aluminium, magnesium and zinc alloys need special pretreatments and, unless otherwise agreed, relatively thick copper, bronze or nickel undercoats before tin-cobalt plating.

What the purchaser must specify

Clause 4 lists the information that must be given in writing when ordering parts. This includes the standard reference, the basis metal, the significant surface to be plated, any areas where minimum thickness applies, acceptable contact marks, special pretreatment, tensile strength and heat treatment needs, undercoat requirements, thickness and adhesion test requirements, finish approval, and the sampling plan.

This matters because the standard relies on the order or drawing to define what must be plated and how it will be checked. If the significant surface or acceptable defects are not identified, the processor cannot reliably judge conformity.

Designation and thickness

Clause 5 sets the designation format. The designation includes the basis metal, optional undercoat, any stress-relief heat treatment prior to electroplating (SR), the coating symbol, the minimum local thickness, any hydrogen-embrittlement-relief heat treatment after electroplating (ER), and any supplementary treatments. Clause 5.5 gives examples showing how these elements are written together.

Clause 6.4 says the coating thickness specified in the designation is the minimum local thickness. The thickness is measured on the significant surface, with the measurement area defined by what can be touched by a 20 mm ball unless the purchaser specifies otherwise. Table 1 gives the minimum thicknesses by basis metal and service condition, so the order must match the intended environment and substrate.

Appearance, adhesion, corrosion evaluation and heat treatment

Clause 6.2 requires significant surfaces to be free from visible blisters, pits, roughness, cracks, uncoated areas, stains or discoloration when viewed with the unaided eye or corrected vision. Unavoidable contact marks and defects on non-significant surfaces are acceptable only where the purchaser has agreed them.

Clause 6.5 allows adhesion testing by the thermal shock test in ISO 2819, with a 1 h heating period. Clause 6.6 provides quality-evaluation tests for controlling coating quality and continuity, using the test methods in Table 2 and the rating system of ISO 10289, with a minimum rating of 9 after corrosion testing.

Clause 6.7 and 6.8 deal with embrittlement risk. Steel parts with ultimate tensile strength equal to or greater than 1 000 MPa need stress-relief heat treatment before cleaning and metal deposition, and similar high-strength or surface-hardened parts need hydrogen-embrittlement-relief heat treatment after electroplating. The document also points to ISO 10587 and ISO 15724 for checking the effectiveness of that treatment.

Sampling

Clause 7 requires a random sample from the inspection lot, using the size and acceptance plans of ISO 4519. In practice, this ties the coating checks to a defined lot-inspection method instead of ad hoc inspection.

What terms does SIST EN ISO 26945:2011 define?

• Basis metal - The underlying metal or alloy that receives the coating; the designation starts from this material.
• Significant surface - The surface area that is intended to receive the coating and is used for thickness and appearance checks.
• Minimum local thickness - The lowest thickness allowed at a point on the significant surface.
• Undercoat - A preliminary coating layer placed under the tin-cobalt alloy to improve adhesion or support the final coating.
• Stress-relief heat treatment prior to electroplating (SR) - A heat treatment applied before plating to reduce internal stresses in the part.
• Hydrogen-embrittlement-relief heat treatment after electroplating (ER) - A post-plating heat treatment used to reduce the risk of hydrogen embrittlement.
• Service condition number - The severity level used in the corrosion-test table: 3 for severe outdoor service, 2 for moderate indoor service with condensation, and 1 for mild dry indoor service.

Who uses SIST EN ISO 26945:2011?

SIST EN ISO 26945:2011 is used by buyers and design engineers who need to specify decorative tin-cobalt coatings on drawings, purchase orders or product specifications. It is also used by electroplating shops that apply the coating by rack or barrel plating, and by quality managers and inspectors who verify appearance, thickness, adhesion, corrosion performance and lot sampling.

The standard is relevant for manufacturers of coated metal parts where decorative brightness matters, including complicated shapes such as nuts, bolts and rivets. It also supports laboratory testing teams that measure coating thickness and carry out the adhesion, corrosion and hydrogen-embrittlement checks named in the document.

What changed in SIST EN ISO 26945:2011 from the previous edition?

This edition replaces SIST EN ISO 26945:2009. The ISO text is identified as the second edition of ISO 26945 and as a minor revision of ISO 26945:2008, and the European adoption supersedes EN ISO 26945:2008.

Which standards are used with SIST EN ISO 26945:2011?

Standard	What it contributes
ISO 1463	Microscopical thickness measurement
ISO 2064	Definitions and conventions for thickness measurement
ISO 2080	Vocabulary for surface treatment and metallic coatings
ISO 2819	Adhesion test methods, including thermal shock
ISO 3497	X-ray spectrometric thickness measurement
ISO 4519	Sampling procedures by attributes
ISO 4541	Corrodkote corrosion test
ISO 9220	Scanning electron microscope thickness method
ISO 9587	Pretreatment of iron or steel to reduce hydrogen embrittlement risk
ISO 9588	Post-coating treatments to reduce hydrogen embrittlement risk
ISO 10289	Rating of corrosion-test specimens and manufactured articles
ISO 10587	Test for residual embrittlement in threaded articles and rods
ISO 15724	Electrochemical measurement of diffusible hydrogen in steels

The introduction also cites ISO 2179 when comparing the coating with tin-nickel alloy coatings, and the bibliography points to ISO 27830, ISO 27831-1 and ISO 27831-2 as related guidance on specifying and preparing metal surfaces.

What does the SIST EN ISO 26945:2011 document contain?

The document contains designation rules, purchaser-information requirements, and coating requirements for basis material, appearance, undercoats, thickness, adhesion, quality evaluation and heat treatment. Table 1 sets the minimum thicknesses by basis metal and service condition, while Table 2 sets corrosion-test durations for the different service conditions.

Clause 5 gives the designation format and worked examples for simple and more complex coating stacks. Annex A gives the three thickness-measurement methods, guidance on selecting a referee method, the rule for average thickness, and the minimum content of a thickness test report.

SLOVENSKI STANDARD
01-november-2011
1DGRPHãþD
SIST EN ISO 26945:2009
Kovinske in druge anorganske prevleke - Galvanske prevleke kositer-kobaltovih
zlitin (ISO 26945:2011)
Metallic and other inorganic coatings - Electrodeposited coatings of tin-cobalt alloy (ISO
26945:2011)
Metallische und andere anorganische Überzüge - Galvanische Überzüge aus Zinn-
Cobalt-Legierungen (ISO 26945:2011)
Revêtements métalliques et autres revêtements inorganiques - Dépôts électrolytiques
d'alliage étain-cobalt (ISO 26945:2011)
Ta slovenski standard je istoveten z: EN ISO 26945:2011
ICS:
25.220.40 Kovinske prevleke Metallic coatings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 26945
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2011
ICS 25.220.40 Supersedes EN ISO 26945:2008
English Version
Metallic and other inorganic coatings - Electrodeposited coatings
of tin-cobalt alloy (ISO 26945:2011)
Revêtements métalliques et autres revêtements Metallische und andere anorganische Überzüge -
inorganiques - Dépôts électrolytiques d'alliage étain-cobalt Galvanische Überzüge aus Zinn-Cobalt-Legierungen (ISO
(ISO 26945:2011) 26945:2011)
This European Standard was approved by CEN on 8 February 2011.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 26945:2011: E
worldwide for CEN national Members.

Contents Page
Foreword .3

Foreword
This document (EN ISO 26945:2011) 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” 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 August 2011, and conflicting national standards shall be withdrawn at
the latest by August 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 26945:2008.
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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 26945:2011 has been approved by CEN as a EN ISO 26945:2011 without any modification.

INTERNATIONAL ISO
STANDARD 26945
Second edition
2011-02-15
Metallic and other inorganic coatings —
Electrodeposited coatings of tin-cobalt
alloy
Revêtements métalliques et autres revêtements inorganiques — Dépôts
électrolytiques d'alliage étain-cobalt

Reference number
ISO 26945:2011(E)
©
ISO 2011
ISO 26945:2011(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.

©  ISO 2011
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2011 – All rights reserved

ISO 26945:2011(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Essential information to be supplied by the purchaser to the processor.2
5 Designation .3
5.1 General .3
5.2 Designation specification.3
5.3 Basis metal.3
5.4 Designation of heat treatment requirements.4
5.5 Examples.4
6 Requirements.4
6.1 Basis material .4
6.2 Appearance .5
6.3 Undercoats.5
6.4 Thickness .5
6.5 Adhesion .6
6.6 Quality-evaluation test of tin-cobalt alloy coatings .6
6.7 Stress-relief heat treatment prior to electroplating .7
6.8 Hydrogen-embrittlement-relief heat treatment after electroplating .7
7 Sampling .7
Annex A (normative) Methods of measuring the thickness of tin-cobalt alloy coatings .8
Bibliography.10

ISO 26945:2011(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 26945 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings.
This second edition cancels and replaces the first edition (ISO 26945:2008), of which it constitutes a minor
revision.
iv © ISO 2011 – All rights reserved

ISO 26945:2011(E)
Introduction
Electrodeposited coating of tin-cobalt alloy is characterized by its bright surface which is similar to decorative
chromium coating. Hardness and wear-resistance properties of tin-cobalt alloy coatings are not equivalent to
those of chromium coatings, but are similar to those of tin-nickel alloy coatings (see ISO 2179). Thus,
tin-cobalt coatings may be regarded, as far as surface lustre is concerned, as one of the possible alternatives
to chromium coating. Due to its higher current efficiency (more than 70 %), tin-cobalt alloy coatings can be
applied by rack-and-barrel plating processes to a wide range of complicated shapes and sizes, e.g. nuts, bolts,
rivets, etc.
INTERNATIONAL STANDARD ISO 26945:2011(E)

Metallic and other inorganic coatings — Electrodeposited
coatings of tin-cobalt alloy
WARNING — This International Standard may not be compliant with some countries' health and safety
legislations and calls for the use of substances and/or procedures that may be injurious to health if
adequate safety measures are not taken. This International Standard does not address any health
hazards, safety or environmental matters and legislations associated with its use. It is the
responsibility of the user of this International Standard to establish appropriate health, safety and
environmentally acceptable practices and take suitable actions to comply with any national and
international regulations. Compliance with this International Standard does not in itself confer
immunity from legal obligations.
1 Scope
This International Standard specifies electrodeposited coatings of tin-cobalt alloy of approximate composition
75 % (mass fraction) to 80 % (mass fraction) tin, remainder cobalt, as a substitute for decorative chromium
coatings of 0,1 µm to 0,3 µm thickness. Hardness and wear resistance properties of the coatings obtained are
not equivalent to those of chromium coatings, but similar to those of tin-nickel alloy coatings.
Tin-cobalt alloy coatings can be applied by rack or barrel plating processes.
This International Standard does not specify requirements for the surface condition of the basis metal prior to
electroplating.
2 Normative references
The following referenced documents are indispensable for the application 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 coatings —
Vocabulary
ISO 2819, Metallic coatings on metallic substrates — Electrodeposited and chemically deposited coatings —
Review of methods available for testing adhesion
ISO 3497, Metallic coatings — Measurement of coating thickness — X-ray spectrometric methods
ISO 4519, Electrodeposited metallic coatings and related finishes — Sampling procedures for inspection by
attributes
ISO 4541, Metallic and other non-organic coatings — Corrodkote corrosion test (CORR test)
ISO 9220, Metallic coatings — Measurement of coating thickness — Scanning electron microscope method
ISO 26945:2011(E)
ISO 9587, Metallic and other inorganic coatings — Pretreatment of iron or steel to reduce the risk of hydrogen
embrittlement
ISO 9588, Metallic and other inorganic coatings — Post-coating treatments of iron or steel to reduce the risk
of hydrogen embrittlement
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 15724, Metallic and other inorganic coatings — Electrochemical measurement of diffusible hydrogen in
steels — Barnacle electrode method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2064, ISO 2080, ISO 9587 and
ISO 9588 apply.
4 Essential information to be supplied by the purchaser to the processor
When ordering articles to be processed in accordance with this International Standard, the purchaser shall
provide the following information in writing, in, for example, the contract, purchase order, or on the engineering
drawing:
a) the number of this International Standard, ISO 26945, and article designation;
b) the nature, condition and finish of the basis metal if they are likely to affect the serviceability and/or
appearance of the coating (see 6.1);
c) the significant surface of the article to be electroplated, indicated, for example, by drawings or by the
provision of suitably marked samples;
d) additional part of surfaces where the minimum thickness requirements apply;
e) positions where unavoidable contact marks and other defects are acceptable (see 6.2);
f) any requirements for special pretreatment (see 6.1);
g) tensile strength of parts and requirements for heat treatment before and/or after electrodeposition (see
6.7 and 6.8);
h) requirements, nature and thickness of undercoats (see 6.1 and 6.3);
i) requirements for thickness, quality-evaluation test for controlling the quality and continuity of the coating
and test method(s) to be used, and adhesion testing (see 6.4, 6.5 and
...