ASTM B499-09

Standard Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic Basis Metals

SIGNIFICANCE AND USE
The thickness of a coating is often critical to its performance. For most nonferrous coatings on steel, the magnetic method is reliable for measuring coating thickness nondestructively and is suitable for specification acceptance testing and SPC/SQC applications.  
This test method should not be used to determine the thickness of electrodeposited nickel coatings on steel. Test Method B 530 is suitable for that determination.
SCOPE
1.1 This test method covers the use of magnetic instruments for the nondestructive measurement of the thickness of nonmagnetic coatings over ferrous or other magnetic base metals. It is intended to supplement manufacturers’ instructions for the operation of the instruments and is not intended to replace them.
Note 1—Autocatalytically deposited nickel-phosphorus alloys containing more than 8 % phosphorus are sufficiently nonmagnetic to be measured by this test method, as long as the measurement is made prior to any heat treatment.  
1.2 These instruments measure either the magnetic attraction between a magnet and the basis metal, as influenced by the presence of the coating (categorized as “magnetic pull-off”), or the change in magnetic-flux density within the probe (categorized as “electronic”). These instruments cannot distinguish the thickness of individual layers. They can only measure the cumulative thickness of all layers beneath the probe down to the base metal.
1.3 Measurements made in accordance with this test method will be in compliance with the requirements of ISO International Standard 2178 as printed in 1982.
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 14-Apr-2009
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.10 - Test Methods

Relations

• Replaces: ASTM B499-96(2002) - Standard Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic Basis Metals
• Effective Date: 15-Apr-2009
• Referred By: ASTM D5087-02(2021) - Standard Test Method for Determining Amount of Volatile Organic Compound (VOC) Released from Solventborne Automotive Coatings and Available for Removal in a VOC Control Device (Abatement)
• Effective Date: 15-Apr-2009
• Referred By: ASTM B200-22 - Standard Specification for Electrodeposited Coatings of Lead and Lead-Tin Alloys on Steel and Ferrous Alloys
• Effective Date: 15-Apr-2009
• Referred By: ASTM B841-18 - Standard Specification for Electrodeposited Coatings of Zinc Nickel Alloy Deposits
• Effective Date: 15-Apr-2009
• Referred By: ASTM E376-19 - Standard Practice for Measuring Coating Thickness by Magnetic-Field or Eddy Current (Electromagnetic) Testing Methods
• Effective Date: 15-Apr-2009
• Referred By: ASTM B700-20 - Standard Specification for Electrodeposited Coatings of Silver for Engineering Use
• Effective Date: 15-Apr-2009
• Referred By: ASTM B659-90(2021) - Standard Guide for Measuring Thickness of Metallic and Inorganic Coatings
• Effective Date: 15-Apr-2009
• Referred By: ASTM B244-09(2021) - Standard Test Method for Measurement of Thickness of Anodic Coatings on Aluminum and of Other Nonconductive Coatings on Nonmagnetic Basis Metals with Eddy-Current Instruments
• Effective Date: 15-Apr-2009
• Referred By: ASTM G198-17 - Standard Test Method for Determining the Relative Corrosion Performance of Driven Fasteners in Contact with Treated Wood
• Effective Date: 15-Apr-2009
• Referred By: ASTM B635-00(2023) - Standard Specification for Coatings of Cadmium-Tin Mechanically Deposited
• Effective Date: 15-Apr-2009
• Referred By: ASTM B699-86(2021)e1 - Standard Specification for Coatings of Cadmium Vacuum-Deposited on Iron and Steel
• Effective Date: 15-Apr-2009
• Referred By: ASTM B842-23 - Standard Specification for Electrodeposited Coatings of Zinc Iron Alloy Deposits
• Effective Date: 15-Apr-2009
• Referred By: ASTM B733-22 - Standard Specification for Autocatalytic (Electroless) Nickel-Phosphorus Coatings on Metal
• Effective Date: 15-Apr-2009
• Referred By: ASTM B579-22 - Standard Specification for Electrodeposited Coatings of Tin-Lead Alloy (Solder Plate)
• Effective Date: 15-Apr-2009
• Referred By: ASTM B734-97(2018) - Standard Specification for Electrodeposited Copper for Engineering Uses
• Effective Date: 15-Apr-2009

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: B499 − 09 Endorsedby American
Electroplaters’ Society
Endorsed by National
Association of Metal Finishers
Standard Test Method for
Measurement of Coating Thicknesses by the Magnetic
1
Method: Nonmagnetic Coatings on Magnetic Basis Metals
This standard is issued under the fixed designation B499; 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 Department of Defense.
1. Scope* 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method covers the use of magnetic instruments
B530 Test Method for Measurement of Coating Thicknesses
for the nondestructive measurement of the thickness of non-
by the Magnetic Method: Electrodeposited Nickel Coat-
magnetic coatings over ferrous or other magnetic base metals.
ings on Magnetic and Nonmagnetic Substrates
It is intended to supplement manufacturers’instructions for the
operation of the instruments and is not intended to replace
2.2 International Standard:
them.
ISO 2178 Non-Magnetic Coatings on Magnetic Substrate—
3
Measurement of Coating Thickness—Magnetic Method
NOTE 1—Autocatalytically deposited nickel-phosphorus alloys contain-
ing more than 8 % phosphorus are sufficiently nonmagnetic to be
3. Terminology
measured by this test method, as long as the measurement is made prior
to any heat treatment.
3.1 Definitions of Terms Specific to This Standard:
1.2 These instruments measure either the magnetic attrac- 3.1.1 accuracy, n—the measure of the magnitude of error
tionbetweenamagnetandthebasismetal,asinfluencedbythe
between the result of a measurement and the true thickness of
presence of the coating (categorized as “magnetic pull-off”), or the item being measured.
the change in magnetic-flux density within the probe (catego-
3.1.2 adjustment, n—the physical act of aligning a instru-
rizedas“electronic”).Theseinstrumentscannotdistinguishthe
ment’s thickness readings to match those of a known thickness
thickness of individual layers. They can only measure the
sample (removal of bias), in order to improve the accuracy of
cumulative thickness of all layers beneath the probe down to
the instrument on a specific surface or within a specific portion
the base metal.
of its measurement range. An adjustment will affect the
outcome of subsequent readings.
1.3 Measurementsmadeinaccordancewiththistestmethod
will be in compliance with the requirements of ISO Interna- 3.1.3 calibration, n—the high-level, controlled and docu-
tional Standard 2178 as printed in 1982.
mented process of obtaining measurements on traceable cali-
bration standards over the full operating range of the
1.4 The values stated in SI units are to be regarded as the
instrument, then making the necessary instrument adjustments
standard. The values given in parentheses are for information
(as required) to correct any out-of-tolerance conditions.
only.
3.1.3.1 Discussion—Calibration of coating thickness instru-
1.5 This standard does not purport to address all of the
ments is performed by the equipment manufacturer, an autho-
safety concerns, if any, associated with its use. It is the
rized agent, or by an authorized, trained calibration laboratory
responsibility of the user of this standard to establish appro-
in a controlled environment using a documented process. The
priate safety and health practices and determine the applica-
outcome of the calibration process is to restore/realign the
bility of regulatory limitations prior to use.
instrument to meet/exceed the manufacturer’s stated accuracy.
1 2
ThistestmethodisunderthejurisdictionofASTMCommitteeB08onMetallic For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Test Methods. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved April 15, 2009. Published May 2009. Originally the ASTM website.
3
approved in 1969. Last previous edition approved in 2002 as B499 – 96 (2002). Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
DOI: 10.1520/B0499-09. 4th Floor, New York, NY 10036, http://www.ansi.org.
*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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B499 − 09
3.1.4 reference standard, n—aspecimenofknownthickness by an authorized, trained calibration labo
...

This document is not anASTM standard and is intended only to provide the user of anASTM 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.
Endorsed by American
Designation:B499–96 (Reapproved 2002) Designation:B499–09 Electroplaters’ Society
Endorsed by National
Association of Metal Finishers
Standard Test Method for
Measurement of Coating Thicknesses by the Magnetic
1
Method: Nonmagnetic Coatings on Magnetic Basis Metals
This standard is issued under the fixed designation B 499; 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 Department of Defense.
1. Scope
1.1This test method covers the use of magnetic instruments for the nondestructive measurement of the thickness of nonmagnetic
coatings over ferrous or other magnetic base metals. *
1.1 This test method covers the use of magnetic instruments for the nondestructive measurement of the thickness of
nonmagnetic coatings over ferrous or other magnetic base metals. It is intended to supplement manufacturers’instructions for the
operation of the instruments and is not intended to replace them.
NOTE 1—Autocatalytically deposited nickel-phosphorus alloys containing more than 8 % phosphorus are sufficiently nonmagnetic to be measured by
this test method, as long as the measurement is made prior to any heat treatment.
1.2Theseinstrumentsmeasureeitherthemagneticattractionbetweenamagnetandthebasismetal,asinfluencedbythepresence
of the coating, or the reluctance of a magnetic-flux path passing through the coating and the basis metal.
1.2 These instruments measure either the magnetic attraction between a magnet and the basis metal, as influenced by the
presence of the coating (categorized as “magnetic pull-off”), or the change in magnetic-flux density within the probe (categorized
as “electronic”). These instruments cannot distinguish the thickness of individual layers. They can only measure the cumulative
thickness of all layers beneath the probe down to the base metal.
1.3 Measurements made in accordance with this test method will be in compliance with the requirements of ISO International
Standard 2178 as printed in 1982.
1.4
1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.5 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
B 530 Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Electrodeposited Nickel Coatings on
Magnetic and Nonmagnetic Substrates
2.2 International Standard:
3
ISO 2178 Non-Magnetic Coatings on Magnetic Substrate—Measurement of Coating Thickness—Magnetic Method
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
1
This test method is under the jurisdiction of ASTM Committee B08 on Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on
General Test Methods.
Current edition approved April 10, 1996. Published June 1996. Originally published as B499–69. Last previous edition B499–88. Replaces portions of A219.on Test
Methods.
Current edition approved April 15, 2009. Published May 2009. Originally approved in 1969. Last previous edition approved in 2002 as B 499 – 96 (2002).
2
Available from American National Standards Institute, 11 W. 42nd St., 13th Floor, New York, NY 10036.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM 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.
3
Coated standards suitable for many applications of the test method may be purchased from the office of Standard Reference Materials, National Institute of Standards
and Technology, Gaithersburg, MD 20899.
3
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
*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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B499–09
3.1.1 accuracy, n—themeasureofthemag
...