ASTM B907-16(2021)

Standard Specification for Zinc, Tin and Cadmium Base Alloys Used as Solders

ABSTRACT
This specification covers solder metal alloys used as solders for the purpose of joining together two or more metals at temperatures below their melting points. The solder alloy shall conform to the required chemical compositions of cadmium, zinc, tin, lead, antimony, silver, copper, aluminum, bismuth, arsenic, iron, nickel and magnesium. The solder paste shall conform to the required smoothness of textures, powder mesh size, and viscosity.
SCOPE
1.1 This specification covers solder metal alloys (commonly known as soft solders), including zinc-aluminum, zinc-aluminum-copper, zinc-tin, zinc-tin-copper, zinc-cadmium-tin, zinc-cadmium, tin-zinc, cadmium-zinc, cadmium-zinc-silver, and cadmium-silver, used as solders for the purpose of joining together two or more metals at temperatures below their melting points.  
1.1.1 Certain alloys specified in this standard are also used as Thermal Spray Wire in the electronics industry and are covered for this purpose in Specification B943. Specification B833 covers Zinc and Zinc Alloy Wire for Thermal Spraying (Metallizing) used primarily for the corrosion protection of steel (as noted in Annex A1 of this specification).  
1.1.2 Tin base alloys are included in this specification because their use in the electronics industry is different than the major use of the tin and lead solder compositions specified in Specification B32.  
1.1.3 These solders include alloys having a nominal liquidus temperature not exceeding 850°F (455°C).  
1.1.4 This specification includes solder in the form of solid bars, ingots, wire, powder and special forms, and in the form of solder paste.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 Toxicity—Warning—Soluble and respirable forms of cadmium may be harmful to human health and the environment in certain forms and concentrations. Therefore, ingestion and inhalation of cadmium should be controlled under the appropriate regulations of the U.S. Occupational Safety and Health Administration (OSHA). Cadmium-containing alloys and coatings should not be used on articles that will contact food or beverages, or for dental and other equipment that is normally inserted in the mouth. Similarly, if articles using cadmium-containing alloys or coatings are welded, soldered, brazed, ground, flame-cut, or otherwise heated during fabrication, adequate ventilation must be provided to maintain occupational cadmium exposure below the OSHA Permissible Exposure Level (PEL).  
1.4 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use.  
1.5 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: 31-Oct-2021
• ICS: 77.120.60 - Lead, zinc, tin and their alloys
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.04 - Zinc and Cadmium

Relations

• Refers: ASTM B833-20 - Standard Specification for Zinc and Zinc Alloy Wire for Thermal Spraying (Metallizing) for the Corrosion Protection of Steel
• Effective Date: 01-Apr-2020
• Refers: ASTM E88-11(2017) - Standard Practice for Sampling Nonferrous Metals and Alloys in Cast Form for Determination of Chemical Composition
• Effective Date: 01-Sep-2017
• Refers: ASTM B899-16 - Standard Terminology Relating to Non-ferrous Metals and Alloys
• Effective Date: 01-Oct-2016
• Refers: ASTM B899-15 - Standard Terminology Relating to Non-ferrous Metals and Alloys
• Effective Date: 01-Oct-2015
• Refers: ASTM E536-15 - Standard Test Methods for Chemical Analysis of Zinc and Zinc Alloys
• Effective Date: 01-Jun-2015
• Refers: ASTM B899-14 - Standard Terminology Relating to Non-ferrous Metals and Alloys
• Effective Date: 01-Oct-2014
• Refers: ASTM B949-13 - Standard Specification for General Requirements for Zinc and Zinc Alloy Products
• Effective Date: 01-Aug-2013
• Refers: ASTM B943-13 - Standard Specification for Zinc and Tin Alloy Wire Used in Thermal Spraying for Electronic Applications
• Effective Date: 01-Feb-2013
• Refers: ASTM B899-13 - Standard Terminology Relating to Non-ferrous Metals and Alloys
• Effective Date: 01-Feb-2013
• Refers: ASTM B833-13 - Standard Specification for Zinc and Zinc Alloy Wire for Thermal Spraying (Metallizing) for the Corrosion Protection of Steel
• Effective Date: 01-Feb-2013
• Refers: ASTM E88-11 - Standard Practice for Sampling Nonferrous Metals and Alloys in Cast Form for Determination of Chemical Composition
• Effective Date: 01-May-2011
• Refers: ASTM B899-09 - Standard Terminology Relating to Non-ferrous Metals and Alloys
• Effective Date: 01-Oct-2009
• Refers: ASTM B899-09e1 - Standard Terminology Relating to Non-ferrous Metals and Alloys
• Effective Date: 01-Oct-2009
• Refers: ASTM B943-09 - Standard Specification for Zinc and Tin Alloy Wire Used in Thermal Spraying for Electronic Applications
• Effective Date: 01-Oct-2009
• Refers: ASTM B833-09 - Standard Specification for Zinc and Zinc Alloy Wire for Thermal Spraying (Metallizing) for the Corrosion Protection of Steel
• Effective Date: 01-Oct-2009

Overview

ASTM B907-16(2021) - Standard Specification for Zinc, Tin and Cadmium Base Alloys Used as Solders defines requirements for solder metal alloys, commonly known as soft solders, intended for joining two or more metals at temperatures below their melting points. The standard covers a broad range of alloy types and forms, such as zinc-aluminum, zinc-tin, tin-zinc, cadmium-zinc, and related silver, copper, and aluminum-containing compositions. It specifies chemical composition, physical forms (bars, wire, ingots, powder, solder paste), and quality measures for application in both general soldering and specialized industrial uses.

Key Topics

• Alloy Types Covered:

  • Zinc-aluminum, zinc-aluminum-copper
  • Zinc-tin, zinc-tin-copper
  • Tin-zinc
  • Zinc-cadmium, zinc-cadmium-tin
  • Cadmium-zinc, cadmium-zinc-silver
  • Cadmium-silver

• Forms and Physical Characteristics:

  • Solid bars, ingots, wire, powder, special forms
  • Solder paste with specified mesh size, texture, and viscosity

• Chemical Composition:

  • Strict requirements for elements including cadmium, zinc, tin, lead, antimony, silver, copper, aluminum, bismuth, arsenic, iron, nickel, and magnesium

• Temperature Range:

  • Suitable for alloys with a liquidus temperature not exceeding 850°F (455°C)

• Sampling and Testing:

  • Procedures for sampling, specimen preparation, and frequency of testing to assure conformity

• Safety and Regulatory Considerations:

  • Cadmium toxicity warnings and adherence to OSHA regulations
  • Prohibition of cadmium-alloy solders for food and medical contact
  • Safety Data Sheet (SDS) compliance and workplace ventilation requirements

Applications

ASTM B907-16(2021) alloys are used in a variety of industries and applications, including:

• General Soldering:

  • Joining aluminum, copper, and other metals in electrical, automotive, and industrial assembly processes

• Electronics Industry:

  • Tin-based and zinc-based solders commonly used for assembling electronic components
  • Certain alloys are specified for use as thermal spray wire in the manufacturing of capacitors

• Thermal Spraying:

  • Alloys such as zinc-aluminum and zinc-aluminum-copper are employed as thermal spray wire for corrosion protection and in electronic applications (as referenced in ASTM B943 and B833)

• Repairs and Specialized Joining:

  • Repairing galvanized steel, radiator repair, and joining dissimilar metals where specialized melting temperature and strength characteristics are required

• High-Strength and Corrosion-Resistance Applications:

  • Select alloys are used for high-strength joints on aluminum and for situations demanding superior corrosion resistance

Related Standards

• ASTM B32: Specification for tin-lead solder compositions
• ASTM B833: Zinc and zinc alloy wire for thermal spraying for corrosion protection of steel
• ASTM B943: Zinc and tin alloy wire for thermal spraying in electronics
• ASTM B949: General requirements for zinc and zinc alloy products
• ASTM B899: Terminology relating to non-ferrous metals and alloys
• ISO 3815-1 & ISO 3815-2: Standards for zinc and zinc alloy analysis methods
• Other ASTM Methods: E29 (significant digits in test data), E527 (numbering metals), E536 (chemical analysis of zinc)

Practical Value

Adhering to ASTM B907-16(2021) ensures reliable, consistent solder joints, reduced risk of corrosion, and compatibility with a wide variety of base metals. By following this international standard, manufacturers, suppliers, and end-users can specify, test, and implement solder alloys with confidence, knowing they meet industry best practices and regulatory requirements for quality and safety. This standard is essential for industries requiring robust, compliant soldered connections and for those involved in both manufacturing and repair operations across electronics, automotive, and industrial domains.

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:B907 −16 (Reapproved 2021)
Standard Specification for
Zinc, Tin and Cadmium Base Alloys Used as Solders
This standard is issued under the fixed designation B907; 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.
1. Scope ground, flame-cut, or otherwise heated during fabrication,
adequateventilationmustbeprovidedtomaintainoccupational
1.1 Thisspecificationcoverssoldermetalalloys(commonly
cadmium exposure below the OSHA Permissible Exposure
known as soft solders), including zinc-aluminum, zinc-
Level (PEL).
aluminum-copper, zinc-tin, zinc-tin-copper, zinc-cadmium-tin,
1.4 This standard does not purport to address all of the
zinc-cadmium, tin-zinc, cadmium-zinc, cadmium-zinc-silver,
safety concerns, if any, associated with its use. It is the
and cadmium-silver, used as solders for the purpose of joining
responsibility of the user of this standard to become familiar
together two or more metals at temperatures below their
with all hazards including those identified in the appropriate
melting points.
Safety Data Sheet (SDS) for this product/material as provided
1.1.1 Certain alloys specified in this standard are also used
by the manufacturer, to establish appropriate safety, health,
as Thermal Spray Wire in the electronics industry and are
and environmental practices, and determine the applicability
covered for this purpose in Specification B943. Specification
of regulatory limitations prior to use.
B833 covers Zinc and Zinc Alloy Wire for Thermal Spraying
1.5 This international standard was developed in accor-
(Metallizing) used primarily for the corrosion protection of
dance with internationally recognized principles on standard-
steel (as noted in Annex A1 of this specification).
ization established in the Decision on Principles for the
1.1.2 Tin base alloys are included in this specification
Development of International Standards, Guides and Recom-
becausetheiruseintheelectronicsindustryisdifferentthanthe
mendations issued by the World Trade Organization Technical
major use of the tin and lead solder compositions specified in
Barriers to Trade (TBT) Committee.
Specification B32.
1.1.3 These solders include alloys having a nominal liqui-
2. Referenced Documents
dus temperature not exceeding 850°F (455°C).
1.1.4 This specification includes solder in the form of solid
2.1 ASTM Standards:
bars,ingots,wire,powderandspecialforms,andintheformof
B32 Specification for Solder Metal
solder paste.
B833 Specification for Zinc and Zinc Alloy Wire for Ther-
malSpraying(Metallizing)fortheCorrosionProtectionof
1.2 The values stated in inch-pound units are to be regarded
Steel
as standard. The values given in parentheses are mathematical
B899 Terminology Relating to Non-ferrous Metals and Al-
conversions to SI units that are provided for information only
loys
and are not considered standard.
B943 Specification for Zinc and Tin Alloy Wire Used in
1.3 Toxicity—Warning—Soluble and respirable forms of
Thermal Spraying for Electronic Applications
cadmiummaybeharmfultohumanhealthandtheenvironment
B949 Specification for General Requirements for Zinc and
in certain forms and concentrations. Therefore, ingestion and
Zinc Alloy Products
inhalation of cadmium should be controlled under the appro-
E29 Practice for Using Significant Digits in Test Data to
priate regulations of the U.S. Occupational Safety and Health
Determine Conformance with Specifications
Administration(OSHA).Cadmium-containingalloysandcoat-
E46 Test Methods for Chemical Analysis of Lead- and
ings should not be used on articles that will contact food or
Tin-Base Solder (Withdrawn 1994)
beverages, or for dental and other equipment that is normally
E51 Method for Spectrographic Analysis of Tin Alloys by
inserted in the mouth. Similarly, if articles using cadmium-
the Powder Technique (Withdrawn 1983)
containing alloys or coatings are welded, soldered, brazed,
1 2
This specification is under the jurisdiction of ASTM Committee B02 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Nonferrous Metals and Alloys and Alloys and is the direct responsibility of contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Subcommittee B02.04 on Zinc and Cadmium. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Nov. 1, 2021. Published December 2021. Originally the ASTM website.
approved in 2000. Last previous edition approved in 2016 as B907 – 16. DOI: The last approved version of this historical standard is referenced on
10.1520/B0907-16R21. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B907−16 (2021)
TABLE 1 Solder Compositions
Table 1a: Zinc Base Alloys
A,B,C
Composition % Temperature
D
UNS Cd Zn Sn Pb Sb Ag Cu Al Bi As Fe Ni Mg Solidus Liquidus
FCF C
Zn 98 Z30402 0.005 REM 0.003 0.005 0.10 0.015 0.005 1.5–2.5 0.02 0.002 0.02 0.005 0.02 720 382 770 410
Zn 97 Z30505 0.005 REM 0.003 0.005 0.10 0.015 0.005 2.5–3.5 0.02 0.002 0.02 0.005 0.02 720 382 743 395
Zn 96 Z30506 0.005 REM 0.003 0.005 0.10 0.015 0.005 3.5–4.5 0.02 0.002 0.02 0.005 0.02 720 382 720 382
Zn 95 Z30502 0.005 REM 0.003 0.005 0.10 0.015 0.005 4.5–5.5 0.02 0.002 0.02 0.005 0.02 720 382 720 382
Zn 94 Z34530 0.005 REM 0.003 0.005 0.10 0.015 1.3–1.5 3.5–4.5 0.02 0.002 0.02 0.005 0.02 730 388 734 390
Zn 90 Z34550 0.004 88.0–92.0 0.003 0.005 0.10 0.015 3.0–6.0 3.0–6.0 0.02 0.002 0.100 0.005 0.05 720 382 797 425
Zn 87 Z30705 0.005 REM 0.003 0.005 0.10 0.015 0.005 12.5–13.5 0.02 0.002 0.05 0.005 0.02 720 382 815 435
Zn 85 Z30702 0.005 REM 0.003 0.005 0.10 0.015 0.005 14.0–16.0 0.02 0.002 0.06 0.005 0.02 720 382 842 450
Zn 80 Z30800 0.005 REM 0.003 0.005 0.10 0.015 0.005 19.5–20.5 0.02 0.002 0.08 0.005 0.02 720 382 896 480
Zn/Sn 50 Z56900 0.005 REM 49.0–51.0 0.05 0.10 0.015 0.005 0.100 0.02 0.002 0.02 0.005 0.02 388 198 680 360
Zn/Sn 49 Z56930 0.005 REM 47.5–50.5 0.05 0.10 0.015 0.8–1.3 0.100 0.02 0.002 0.02 0.005 0.05 392 200 592 311
E
Zn/Sn 27 Z13371 33.0 26.0–28.0 REM 0.05 0.10 0.015 0.05 0.050 0.02 0.020 0.02 0.005 0.05 351 177 500 260
E
Zn/Cd 90 Z50940 REM 89.0–91.0 0.003 0.05 0.10 0.015 0.05 0.100 0.02 0.002 0.02 0.005 0.05 509 265 738 392
E
Zn/Cd 60 Z50980 REM 59.0–61.0 0.003 0.05 0.10 0.015 0.05 0.100 0.02 0.002 0.02 0.005 0.05 509 265 648 342
Table 1b: Tin Base Alloys
A,B,C
Composition % Temperature
UNS Cd Zn Sn Pb Sb Ag Cu Al Bi As Fe Ni Mg Solidus Liquidus
FCF C
Sn/Zn 60 L13281 0.005 REM 59.0–61.0 0.05 0.10 0.015 0.01 0.100 0.005 0.002 0.02 0.005 0.05 390 199 666 352
Sn/Zn 70 L13271 0.005 REM 69.0–71.0 0.005 0.10 0.015 0.01 0.100 0.005 0.002 0.02 0.005 0.05 390 199 601 316
Sn/Zn 75 L13261 0.004 REM 74.0–76.0 0.20 0.10 0.015 0.05 0.050 0.020 0.020 0.02 0.005 0.05 390 199 572 300
Sn/Zn 80 L13251 0.005 REM 79.0–81.0 0.05 0.10 0.015 0.01 0.100 0.005 0.002 0.02 0.005 0.05 390 199 536 280
Sn/Zn 91 L13241 0.005 REM 90.0–92.0 0.05 0.10 0.015 0.01 0.100 0.005 0.002 0.02 0.005 0.05 390 199 390 199
Table 1c: Cadmium Base Alloys
A,B,C
Composition % Temperature
UNS Cd Zn Sn Pb Sb Ag Cu Al Bi As Fe Ni Mg Solidus Liquidus
FCF C
Cd 60 L01181 REM 39.0–41.0 0.003 0.05 0.10 0.015 0.05 0.100 0.02 0.002 0.02 0.005 0.05 509 265 601 316
Cd 70 L01171 REM 29.0–31.0 0.003 0.05 0.10 0.015 0.05 0.100 0.02 0.002 0.02 0.005 0.05 509 265 572 300
Cd 78 L01255 REM 11.0–13.0 0.003 0.05 0.10 4.5–5.5 0.05 0.100 0.02 0.002 0.02 0.005 0.05 480 249 601 316
Cd 83 L01161 REM 16.0–18.0 0.003 0.05 0.10 0.015 0.05 0.100 0.02 0.002 0.02 0.005 0.05 509 265 509 265
Cd 95 L01331 REM 0.007 0.003 0.05 0.10 4.5–5.5 0.05 0.100 0.02 0.002 0.02 0.005 0.05 640 338 739 393
A
For purposes of acceptance and rejection, the observed value or calculated value obtained from analysis should be rounded to the nearest unit in the last right-hand
place of figures, used in expressing the specified limit, in accordance with the rounding procedure prescribed in Practice E29.
B
All values not given as a range are maximum values unless stated otherwise.
C
Remainder (REM) determined arithmetically by difference.
D
The USN designations were established in accordance with Practice E527. The last digit of a UNS number differentiates between alloys of similar composition.
E
These alloys are listed with the zinc base alloys even though they contain significant amounts of cadmium because their use is similar to those of the other alloys in
Table 1A.
E55 Practice for Sampling Wrought Nonferrous Metals and
2.3 ISO Standards:
Alloys for Determination of Chemical Composition
ISO 3815-1 Zinc and zinc alloys — Part 1:Analysis of solid
E87 Methods for ChemicalAnalysis of Lead,Tin,Antimony
samples by optical emission spectrometry
and Their Alloys (Photometric Method) (Withdrawn
ISO 3815-2 Zinc and zinc alloys — Part 2: Analysis by
1983)
inductively coupled plasma optical emission spectrometry
E88 Practice for Sampling Nonferrous Metals and Alloys in
2.4 Military Standard:
Cast Form for Determination of Chemical Composition
Mil-Std-129 Marking for Shipment and Storage
E527 Practice for Numbering Metals and Alloys in the
3. Terminology
Unified Numbering System (UNS)
E536 Test Methods for Chemical Analysis of Zinc and Zinc 3.1 Terms shall be defined in accordance with Terminology
B899.
Alloys
2.2 Federal Standard:
4. Classification
Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
4.1 Type Designation—The type designation uses the fol-
lowing symbols to properly identify the material:
4 5
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B907−16 (2021)
TABLE 2 Form TABLE 3 Powder Mesh Size
Symbol Form Size Symbol Powder Mesh Size
B Bar A <325
I Ingot B <200
P Powder C <100
R Ribbon D <60
A
S Special
W Wire
A
Includes pellets, preforms, etc.
TABLE 4 Frequency of Sampling
Size of Lot, lb (kg) Number of Samples (spools, coils,
containers or pieces)
Up to 1000 (450), incl 3
4.1.1 Alloy Composition—The composition is identified by
Over 1000 to 10 000 (450 to 4500), incl 5
Over 10 000 (4500) 10
a two or four-letter symbol and a number. The letters typically
indicate the chemical symbol for the critical element in the
solder and the number indicates the nominal percentage, by
weight, of the critical element in the solder (see Table 1).
4.1.2 Form—The form is indicated by a single letter in
8.2 The following variables must be taken into account
accordance with Table 2.
when relating one viscosity measurement to another: type of
4.1.3 Powder Mesh Size (applicable only to solder paste)—
viscometer used, spindle size and shape, speed (r/min), tem-
The powder mesh size is identified by a single letter in
perature and the recent mixing history of the sample, and the
accordance with Table 3.
use or non-use of a helipath.
5. Ordering Information
9. Dimensions and Unit Weight
5.1 Orders for material under this specification indicate the
9.1 Bar and Ingot Solder—The dimensions and unit weight
following information, as required, to adequately describe the
ofbarandingotsolderwillbeasagreeduponbetweensupplier
desired material.
and purchaser.
5.1.1 Type designation (see 4.1),
9.2 Wire Solder—The dimensions and unit weight of wire
5.1.2 Detailed requirements for special forms,
solder are specified in 5.1.3 and 5.1.4. The tolerance on
5.1.3 Dimensions of ribbon and wire solder (see 9.2),
specified outside diameter shall be 65% or 60.002 in.
5.1.4 Unit weight,
(0.05 mm), whichever is greater.
5.1.5 Packaging (see Section 18),
5.
...