ASTM D5796-20

Standard Test Method for Measurement of Dry Film Thickness of Thin-Film Coil-Coated Systems by Destructive Means Using a Boring Device

SIGNIFICANCE AND USE
3.1 Measurement of dry film thickness of organic coatings by physically cutting through the film and optically observing and measuring the thickness offers the advantage of direct measurement as compared with nondestructive means.  
3.2 Constituent coating layers of an overall thickness of a coating system can usually be measured individually by this test method, provide adhesion between each layer is sufficient. (However, this can be difficult in cases where the primer, topcoat, or multiple coating layers have the same, or very similar, appearance.)
FIG. 1 Typical Crater Formed by Boring Device
Note 1: The drawing is not to scale. It is for illustration purposes only.
Note 2: θ = 5.710593°
Tan θ = A/B = 0.1
A = 0.1B
SCOPE
1.1 This test method covers the measurement of dry film thickness (DFT) of coating films by microscopic observation of a precision-cut, shallow-angle crater bored into the coating film. This crater reveals cross sectional layers appearing as rings, whose width is proportional to the depth of the coating layer(s) and allows for direct calculation of dry film thickness.  
1.1.1 The Apparatus, Procedure, and Precision and Bias discussions include Method A and Method B. Method A involves the use of an optical measurement apparatus which is no longer commercially available, but remains a valid method of dry film measurement. Method B is a software driven measurement procedure that supersedes Method A.  
1.2 The substrate may be any rigid, metallic material, such as cold-rolled steel, hot-dipped galvanized steel, aluminum, etc. The substrate must be planar with the exception of substrates exhibiting “coil set,” which may be held level by the use of the clamping tool on the drilling device.
Note 1: Variations in the surface profile of the substrate may result in misrepresentative organic coating thickness readings. This condition may exist over substrates such as hot-dipped, coated steel sheet. This is true of all “precision cut” methods that are used to determine dry film thickness of organic coatings. This is why several measurements across the strip may be useful if substrate surface profile is suspect.  
1.3 The range of thickness measurement is 0 to 3.5 mils (0 to 89 μm).
Note 2: For DFT measurements of films greater than 3.5 mils (89μm), but less than 63 mils (1600 μm), a 45° borer may be used in accordance with this test method, with the exception of 6.8, where the micrometer reading would provide a direct read-out, and division by ten would be unnecessary per 4.3.1 Method A.  
1.4 Measurements may be made on coil-coated sheet, certain formed products, or on test panels.  
1.5 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: 30-Jun-2020
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.53 - Coil Coated Metal

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: D5796 − 20
Standard Test Method for
Measurement of Dry Film Thickness of Thin-Film Coil-
Coated Systems by Destructive Means Using a Boring
1
Device
This standard is issued under the fixed designation D5796; 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 1.4 Measurements may be made on coil-coated sheet, cer-
tain formed products, or on test panels.
1.1 This test method covers the measurement of dry film
thickness(DFT)ofcoatingfilmsbymicroscopicobservationof 1.5 The values stated in SI units are to be regarded as the
a precision-cut, shallow-angle crater bored into the coating standard. The values given in parentheses are for information
film. This crater reveals cross sectional layers appearing as only.
rings, whose width is proportional to the depth of the coating
1.6 This standard does not purport to address all of the
layer(s) and allows for direct calculation of dry film thickness.
safety concerns, if any, associated with its use. It is the
1.1.1 The Apparatus, Procedure, and Precision and Bias
responsibility of the user of this standard to establish appro-
discussions include Method A and Method B. Method A
priate safety, health, and environmental practices and deter-
involves the use of an optical measurement apparatus which is
mine the applicability of regulatory limitations prior to use.
no longer commercially available, but remains a valid method
1.7 This international standard was developed in accor-
of dry film measurement. Method B is a software driven
dance with internationally recognized principles on standard-
measurement procedure that supersedes Method A.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.2 The substrate may be any rigid, metallic material, such
mendations issued by the World Trade Organization Technical
as cold-rolled steel, hot-dipped galvanized steel, aluminum,
Barriers to Trade (TBT) Committee.
etc. The substrate must be planar with the exception of
substrates exhibiting “coil set,” which may be held level by the
2. Referenced Documents
use of the clamping tool on the drilling device.
2
2.1 ASTM Standards:
NOTE 1—Variations in the surface profile of the substrate may result in
D3794 Guide for Testing Coil Coatings
misrepresentative organic coating thickness readings. This condition may
exist over substrates such as hot-dipped, coated steel sheet. This is true of
3. Significance and Use
all “precision cut” methods that are used to determine dry film thickness
of organic coatings. This is why several measurements across the strip
3.1 Measurement of dry film thickness of organic coatings
may be useful if substrate surface profile is suspect.
by physically cutting through the film and optically observing
1.3 The range of thickness measurement is 0 to 3.5 mils (0
and measuring the thickness offers the advantage of direct
to 89 µm).
measurement as compared with nondestructive means.
NOTE 2—For DFTmeasurements of films greater than 3.5 mils (89µm), 3.2 Constituent coating layers of an overall thickness of a
but less than 63 mils (1600 µm), a 45° borer may be used in accordance
coating system can usually be measured individually by this
with this test method, with the exception of 6.8, where the micrometer
test method, provide adhesion between each layer is sufficient.
reading would provide a direct read-out, and division by ten would be
(However, this can be difficult in cases where the primer,
unnecessary per 4.3.1 Method A.
topcoat, or multiple coating layers have the same, or very
similar, appearance.)
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
2
Subcommittee D01.53 on Coil Coated Metal. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2020. Published July 2020. Originally approved contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
in 1995. Last previous edition approved in 2015 as D5796 – 10 (2015). DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D5796-20. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D5796 − 20
verification should be done at interval
...

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: D5796 − 10 (Reapproved 2015) D5796 − 20
Standard Test Method for
Measurement of Dry Film Thickness of Thin-Film Coil-
Coated Systems by Destructive Means Using a Boring
1
Device
This standard is issued under the fixed designation D5796; 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
1.1 This test method covers the measurement of dry film thickness (DFT) of coating films by microscopic observation of a
precision-cut, shallow-angle crater bored into the coating film. This crater reveals cross sectional layers appearing as rings, whose
width is proportional to the depth of the coating layer(s) and allows for direct calculation of dry film thickness.
1.1.1 The Apparatus, Procedure, and Precision and Bias discussions include Method A and Method B. Method A involves the
use of an optical measurement apparatus which is no longer commercially available, but remains a valid method of dry film
measurement. Method B is a software driven measurement procedure that supersedes Method A.
1.2 The substrate may be any rigid, metallic material, such as cold-rolled steel, hot-dipped galvanized steel, aluminum, etc. The
substrate must be planar with the exception of substrates exhibiting “coil set,” which may be held level by the use of the clamping
tool on the drilling device.
NOTE 1—Variations in the surface profile of the substrate may result in misrepresentative organic coating thickness readings. This condition may exist
over substrates such as hot-dipped, coated steel sheet. This is true of all “precision cut” methods that are used to determine dry film thickness of organic
coatings. This is why several measurements across the strip may be useful if substrate surface profile is suspect.
1.3 The range of thickness measurement is 0 to 3.5 mils (0 to 89 μm).
NOTE 2—For DFT measurements of films greater than 3.5 mils (89μm), but less than 63 mils (1600 μm), a 45° borer may be used in accordance with
this test method, with the exception of 6.8, where the micrometer reading would provide a direct read-out, and division by ten would be unnecessary per
4.3.1 Method A.
1.4 Measurements may be made on coil-coated sheet, certain formed products, or on test panels.
1.5 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 safety, health, and healthenvironmental 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:
D3794 Guide for Testing Coil Coatings
3. Significance and Use
3.1 Measurement of dry film thickness of organic coatings by physically cutting through the film and optically observing and
measuring the thickness offers the advantage of direct measurement as compared with nondestructive means.
1
This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.53 on Coil Coated Metal.
Current edition approved June 1, 2015July 1, 2020. Published June 2015July 2020. Originally approved in 1995. Last previous edition approved in 20102015 as
D5796 – 10.D5796 – 10 (2015). DOI: 10.1520/D5796-10R15.10.1520/D5796-20.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D5796 − 20
3.2 Constituent coating layers of an overall thickness of a coating system can usually be measured individually by this test
method, provide adh
...