ASTM B545-22

Standard Specification for Electrodeposited Coatings of Tin

ABSTRACT
This specification covers the requirements for electrodeposited tin coatings applied to metallic articles to provide a low contact resistance surface, to protect against corrosion, to facilitate soldering, to provide anti-galling properties, and to be a stop-off coating in the nitriding of high-strength steels. This specification does not cover hot-dipped tin or other non-electrodeposited coatings, and mill products. Coatings shall be grouped into six service classes, which is based on the minimum thickness and severity of service required for the coating, and three surface appearance types, which is based on the type electroplating process employed. The surface appearance types are matte tin electrodeposits, bright tin electrodeposits, and flow-brightened electrodeposits. Coatings shall be sampled, tested and conform accordingly to specified requirements as to appearance, purity, local and mean thickness, integrity (including gross defects, mechanical damage, and porosity), adhesion, solderability, and hydrogen embrittlement relief.
SCOPE
1.1 This specification covers the requirements for electrodeposited (electroplated) coatings of tin applied to metallic articles. Tin coatings are used to provide a low contact-resistance surface, to protect against corrosion (see 1.2), to facilitate soldering, to provide anti-galling properties, and to be a stopoff coating in the nitriding of high-strength steels.  
1.2 Some corrosion can be expected from tin coatings exposed outdoors. In normal indoor exposure, tin is protective on iron, steel, nickel, copper, and their alloys. Corrosion can be expected at discontinuities in the coating (such as pores) due to galvanic couples formed between the tin and the underlying metal through the discontinuities, especially in humid atmospheres. Porosity increases as the coating thickness decreases, so that minimum thicknesses must be specified for each application. Parts coated with tin can be assembled safely in contact with iron and steel, tin-coated aluminum, yellow chromated zinc, cadmium, and solder coatings. (See X5.1 for oxidation and corrosion properties.)  
1.3 This specification applies to electroplated coatings of not less than 99 % tin (except where deliberately alloyed for special purposes, as stated in X6.3) obtained from any of the available tin electroplating processes (see 4.3).  
1.4 This specification does not apply to hot-dipped tin or other non-electrodeposited coating; it also does not apply to mill products. For mill products, refer to Specifications A623 or A623M.  
1.5 Units—The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 14-Nov-2022
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.06 - Soft Metals

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B545 −22
Standard Specification for
1
Electrodeposited Coatings of Tin
This standard is issued under the fixed designation B545; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* 1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.1 Thisspecificationcoverstherequirementsforelectrode-
ization established in the Decision on Principles for the
posited (electroplated) coatings of tin applied to metallic
Development of International Standards, Guides and Recom-
articles. Tin coatings are used to provide a low contact-
mendations issued by the World Trade Organization Technical
resistance surface, to protect against corrosion (see 1.2), to
Barriers to Trade (TBT) Committee.
facilitatesoldering,toprovideanti-gallingproperties,andtobe
a stopoff coating in the nitriding of high-strength steels.
2. Referenced Documents
1.2 Some corrosion can be expected from tin coatings
2
2.1 ASTM Standards:
exposed outdoors. In normal indoor exposure, tin is protective
A623Specification for Tin Mill Products, General Require-
oniron,steel,nickel,copper,andtheiralloys.Corrosioncanbe
ments
expectedatdiscontinuitiesinthecoating(suchaspores)dueto
A623MSpecification for Tin Mill Products, General Re-
galvanic couples formed between the tin and the underlying
quirements [Metric]
metal through the discontinuities, especially in humid atmo-
B183Practice for Preparation of Low-Carbon Steel for
spheres. Porosity increases as the coating thickness decreases,
Electroplating
so that minimum thicknesses must be specified for each
B242Guide for Preparation of High-Carbon Steel for Elec-
application. Parts coated with tin can be assembled safely in
troplating
contact with iron and steel, tin-coated aluminum, yellow
B246Specification for Tinned Hard-Drawn and Medium-
chromated zinc, cadmium, and solder coatings. (See X5.1 for
Hard-Drawn Copper Wire for Electrical Purposes
oxidation and corrosion properties.)
B281Practice for Preparation of Copper and Copper-Base
1.3 This specification applies to electroplated coatings of
Alloys for Electroplating and Conversion Coatings
not less than 99% tin (except where deliberately alloyed for
B320Practice for Preparation of Iron Castings for Electro-
special purposes, as stated in X6.3) obtained from any of the
plating
available tin electroplating processes (see 4.3).
B322Guide for Cleaning Metals Prior to Electroplating
1.4 This specification does not apply to hot-dipped tin or B374Terminology Relating to Electroplating
other non-electrodeposited coating; it also does not apply to B487Test Method for Measurement of Metal and Oxide
mill products. For mill products, refer to Specifications A623 Coating Thickness by Microscopical Examination of
or A623M. Cross Section
B499Test Method for Measurement of CoatingThicknesses
1.5 Units—The values stated in SI units are to be regarded
by the Magnetic Method: Nonmagnetic Coatings on
as the standard. The values given in parentheses are for
Magnetic Basis Metals
information only.
B504Test Method for Measurement of Thickness of Metal-
1.6 This standard does not purport to address all of the
lic Coatings by the Coulometric Method
safety concerns, if any, associated with its use. It is the
B507Practice for Design ofArticles to Be Electroplated on
responsibility of the user of this standard to establish appro-
Racks
priate safety, health, and environmental practices and deter-
B542Terminology Relating to Electrical Contacts andTheir
mine the applicability of regulatory limitations prior to use.
Use
1
This specification is under the jurisdiction of ASTM Committee B08 on
Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee
2
B08.06 on Soft Metals. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 15, 2022. Published December 2022. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approvedin1971.Lastpreviouseditionapprovedin2021asB545–13(2021).DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/B0545-22. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B545 − 13 (Reapproved 2021) B545 − 22
Standard Specification for
1
Electrodeposited Coatings of Tin
This standard is issued under the fixed designation B545; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope Scope*
1.1 This specification covers the requirements for electrodeposited (electroplated) coatings of tin applied to metallic articles. Tin
coatings are used to provide a low contact-resistance surface, to protect against corrosion (see 1.2), to facilitate soldering, to
provide anti-galling properties, and to be a stopoff coating in the nitriding of high-strength steels.
1.2 Some corrosion can be expected from tin coatings exposed outdoors. In normal indoor exposure, tin is protective on iron, steel,
nickel, copper, and their alloys. Corrosion can be expected at discontinuities in the coating (such as pores) due to galvanic couples
formed between the tin and the underlying metal through the discontinuities, especially in humid atmospheres. Porosity increases
as the coating thickness decreases, so that minimum thicknesses must be specified for each application. Parts coated with tin can
be assembled safely in contact with iron and steel, tin-coated aluminum, yellow chromated zinc, cadmium, and solder coatings.
(See X5.1 for oxidation and corrosion properties.)
1.3 This specification applies to electroplated coatings of not less than 99 % tin (except where deliberately alloyed for special
purposes, as stated in X6.3) obtained from any of the available tin electroplating processes (see 4.3).
1.4 This specification does not apply to hot-dipped tin or other non-electrodeposited coating; it also does not apply to mill
products. For mill products, refer to Specifications A623 or A623M.
1.5 Units—The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information
only.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
1
This specification is under the jurisdiction of ASTM Committee B08 on Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee B08.06 on Soft
Metals.
Current edition approved May 1, 2021Nov. 15, 2022. Published May 2021December 2022. Originally approved in 1971. Last previous edition approved in 20132021 as
B545 – 13.B545 – 13(2021). DOI: 10.1520/B0545-13R21.10.1520/B0545-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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B545 − 22
A623 Specification for Tin Mill Products, General Requirements
A623M Specification for Tin Mill Products, General Requirements [Metric]
B32 Specification for Solder Metal
B183 Practice for Preparation of Low-Carbon Steel for Electroplating
B242 Guide for Preparation of High-Carbon Steel for Electroplating
B246 Specification for Tinned Hard-Drawn and Medium-Hard-Drawn Copper Wire for Electrical Purposes
B281 Practice for Preparation of Copper and Copper-Base Alloys for Electroplating and Conversion Coatings
B320 Practice for Preparation of Iron Castings for Electroplating
B322 Guide for Cleaning Metals Prior to Electroplating
B374 Terminology Relating to Electroplating
B487 Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Se
...