ASTM B489-85(2023)

Standard Practice for Bend Test for Ductility of Electrodeposited and Autocatalytically Deposited Metal Coatings on Metals

SIGNIFICANCE AND USE
4.1 The routine measurement of the ductility of electrodeposited and autocatalytically deposited metal coatings can be useful in process control, especially when the electroplating process is used for decorative and engineering purposes.
SCOPE
1.1 This practice covers a test procedure for determining the ductility of electrodeposited and autocatalytically deposited coatings on sheet or strip basis metals. The purpose of the test is to determine the resistance of metal coatings to cracking during distortion.2  
1.2 Test Methods E8 can be used if the coatings are too ductile and require mandrels too small to be practical.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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 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: 30-Apr-2023
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.10 - Test Methods

Relations

• Refers: ASTM B177-01(2006)e1 - Standard Guide for Engineering Chromium Electroplating
• Effective Date: 01-Apr-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM E8-04 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Apr-2004
• Refers: ASTM E8-03 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 10-Jul-2003
• Refers: ASTM B177-93 - Standard Guide for Engineering Chromium Electroplating
• Effective Date: 10-Nov-2001
• Refers: ASTM B177-01 - Standard Guide for Engineering Chromium Electroplating
• Effective Date: 10-Nov-2001
• Refers: ASTM E8-01 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 10-Oct-2001
• Refers: ASTM E8-01e2 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 10-Oct-2001
• Refers: ASTM E8-01e1 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 10-Oct-2001
• Refers: ASTM E8-00b - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 10-Oct-2001
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM B489-85(2023): Standard Practice for Bend Test for Ductility of Electrodeposited and Autocatalytically Deposited Metal Coatings on Metals provides a widely recognized procedure for evaluating the ductility and resistance to cracking of metallic coatings on metal substrates. Developed by ASTM International, this standard supports process control and quality assurance in electroplating and autocatalytic coating operations, particularly for applications where appearance and durability are essential.

This standard is applicable to sheet or strip metals coated by electrodeposition or autocatalytic (chemical) methods. The bend test outlined helps manufacturers and quality laboratories determine the suitability of coatings for both decorative and engineering uses by assessing their ability to endure deformation without cracking.

Key Topics

• Ductility Measurement: Determines the resistance of coatings to cracking under mechanical deformation, an important factor for plated or coated metals used in forming, fabrication, and service conditions.
• Test Methodology: Involves bending flat, prepared specimens over progressively smaller mandrels and inspecting for surface cracks, providing a comparative index of ductility.
• Mandrel and Specimen Requirements: Specifies specimen preparation (width, length, edge finishing) and the use of a graduated set of mandrels for accurate ductility evaluation.
• Applicability Limits: Recommends alternative methods, such as ASTM E8, for coatings exhibiting extreme ductility.
• Data Interpretation: Describes evaluation criteria for coating performance, including the significance of crack size and location, especially in multi-layer coatings.
• Safety Responsibility: Emphasizes that users must consider appropriate safety, health, and environmental measures when conducting tests.
• International Harmonization: Developed in alignment with WTO Technical Barriers to Trade (TBT) principles, supporting global trade and standardization.

Applications

ASTM B489-85(2023) is valuable for various sectors, including:

• Process Control in Metal Finishing: Routine bend tests allow platers and manufacturers to monitor and adjust plating or autocatalytic deposition processes, ensuring coating ductility meets requirements.
• Quality Assurance and Product Validation: Used by quality control labs and inspectors to confirm coatings will withstand mechanical deformation during manufacturing, handling, and service.
• Decorative and Engineering Coatings: Essential for products where decorative finishes must also endure bending, shaping, or service stresses without visual or functional failure.
• Material Selection and Development: Assists design engineers and material scientists in selecting suitable coating systems for parts subject to forming operations.
• Supplier Audits and Compliance: Supports verification of supplier conformity to contractual requirements for coating ductility.

Typical users include manufacturers of automotive components, appliances, electronics, hardware, and architectural metal products, as well as independent testing laboratories and plating shops.

Related Standards

• ASTM B177 - Guide for Engineering Chromium Electroplating
• ASTM E8/E8M - Test Methods for Tension Testing of Metallic Materials
• ASTM D1193 - Specification for Reagent Water

For more information about related standards or to purchase ASTM B489-85(2023), visit ASTM International.

---

Keywords: ASTM B489, bend test, ductility test, electrodeposited coatings, autocatalytically deposited coatings, metal coatings, process control, quality assurance, electroplating standards, mechanical testing, coating durability, international standards.

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: B489 − 85 (Reapproved 2023)
Standard Practice for
Bend Test for Ductility of Electrodeposited and
Autocatalytically Deposited Metal Coatings on Metals
This standard is issued under the fixed designation B489; 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 3. Summary of Practice
3.1 The practice consists of bending a narrow strip of the
1.1 This practice covers a test procedure for determining the
ductility of electrodeposited and autocatalytically deposited electroplated or coated article over a mandrel. An elongation
measurement is obtained from the smallest diameter mandrel
coatings on sheet or strip basis metals. The purpose of the test
is to determine the resistance of metal coatings to cracking that does not cause the coating to fracture.
during distortion.
4. Significance and Use
1.2 Test Methods E8 can be used if the coatings are too
4.1 The routine measurement of the ductility of electrode-
ductile and require mandrels too small to be practical.
posited and autocatalytically deposited metal coatings can be
1.3 The values stated in SI units are to be regarded as
useful in process control, especially when the electroplating
standard. No other units of measurement are included in this
process is used for decorative and engineering purposes.
standard.
5. Apparatus
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.1 Series of Mandrels, with diameters from 6 mm to 50
responsibility of the user of this standard to establish appro-
mm, in 3 mm steps with lengths of 100 mm to 150 mm so they
priate safety, health, and environmental practices and deter-
can be held in a vise.
mine the applicability of regulatory limitations prior to use.
5.2 Micrometer, to measure the thickness of the test speci-
1.5 This international standard was developed in accor-
mens.
dance with internationally recognized principles on standard-
5.3 Guillotine Shears or other device to cut the specimens to
ization established in the Decision on Principles for the
size.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5.4 File or Grinder to remove burrs and to round or chamfer
Barriers to Trade (TBT) Committee.
edges.
5.5 Vise, to hold mandrels.
2. Referenced Documents
5.6 Magnifier, 10×.
2.1 ASTM Standards:
B177 Guide for Engineering Chromium Electroplating
6. Test Specimen
D1193 Specification for Reagent Water
6.1 Flat specimens, 10 mm wide, and not less than 150 mm
E8 Test Methods for Tension Testing of Metallic Materials
long, shall be cut from the electroplated or coated article if the
[Metric] E0008_E0008M
shape permits, no closer than 25 mm from the edges. Guillotine
shears are preferred, but any convenient method may be used.
Basis metal thickness and temper shall be suitable to permit
This practice is under the jurisdiction of ASTM Committee B08 on Metallic
bending around the smallest diameter mandrel, if necessary.
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on
Low-carbon AISI 1010 to 1025 steel strip or sheet, 0.25 mm to
Test Methods.
1.0 mm thick is usually suitable. Basis metals that have low
Current edition approved May 1, 2023. Published June 2023. Originally
approved in 1968. Last previous edition approved in 2018 as B489 – 85 (2018).
ductility can initiate cracks that can propagate through the
DOI: 10.1520/B0489-85R23.
coatings. The procedure indicated in 6.2 shall then be followed.
For a discussion and theory for this test see Mohrnheim, A. F., “The Bend Test
for Measuring the Strain Limit of Surfaces,” Plating, Vol 50, 1963, pp. 1094 – 1099.
6.2 When the shape is such that a test specimen cannot be
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
obtained from the part, a test panel may be prepared of
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
appropriate basis metal, such as low-carbon steel (see 6.1),
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. with the same coating system in the same baths. The panel shall
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B489 − 85 (2023)
be sufficiently large to obtain several pieces after trimming the nickel to an intermediate copper layer or to the basis metal.
25 mm from the edges. The specimens shall be prepared in Methods for determining this are provided in the Appendix. A
accordance with 6.1. Brass or copper panels may be used positive test for copper or iron signifies failure.
instead of copper-electroplated zinc alloy panels.
7.3 Except for very ductile coatings, the apparent ductility is
6.3 The long edges of the test pieces shall be rounded or an inverse function of the thickness. If the test is to be used to
chamfered by filing or grinding. evaluate the electroplating or autocatalytic process by periodi-
cally testing the ductility of coatings produced by the process,
7. Procedure
all specimens used must have approximately the same coating
...