ASTM D5796-03

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D5796–03
Standard Test Method for
Measurement of Dry Film Thickness of Thin-Film Coil-
Coated Systems by Destructive Means Using a Boring
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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 1.5 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information
1.1 This test method covers the measurement of dry film
only.
thickness(DFT)ofcoatingfilmsbymicroscopicobservationof
1.6 This standard does not purport to address all of the
a precision-cut, shallow-angle crater bored into the coating
safety concerns, if any, associated with its use. It is the
film. This crater reveals cross sectional layers appearing as
responsibility of the user of this standard to establish appro-
rings, whose width is proportional to the depth of the coating
priate safety and health practices and determine the applica-
layer(s) and allows for direct calculation of dry film thickness.
bility of regulatory limitations prior to use.
1.1.1 The Apparatus, Procedure, and Precision and Bias
discussions include Method A and Method B. Method A
2. Referenced Documents
involves the use of an optical measurement apparatus which is
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2.1 ASTM Standards:
no longer commercially available, but remains a valid method
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D3794 Guide for Testing Coil Coatings
of dry film measurement. Method B is a software driven
measurement procedure that supersedes Method A.
3. Significance and Use
1.2 The substrate may be any rigid, metallic material, such
3.1 Measurement of dry film thickness of organic coatings
as cold-rolled steel, hot-dipped galvanized steel, aluminum,
by physically cutting through the film and optically observing
etc. The substrate must be planar with the exception of
and measuring the thickness offers the advantage of direct
substrates exhibiting “coil set,” which may be held level by the
measurement as compared with nondestructive means.
use of the clamping tool on the drilling device.
3.2 Constituent coating layers of an overall thickness of a
NOTE 1—Variations in the surface profile of the substrate may result in
coating system can usually be measured individually by this
misrepresentative organic coating thickness readings. This condition may
test method, provide adhesion between each layer is sufficient.
exist over substrates such as hot-dipped, coated steel sheet. This is true of
(However, this can be difficult in cases where the primer,
all “precision cut” methods that are used to determine dry film thickness
topcoat, or multiple coating layers have the same, or very
of organic coatings. This is why several measurements across the strip
similar, appearance.)
may be useful if substrate surface profile is suspect.
1.3 The range of thickness measurement is 0 to 3.5 mils (0
4. Apparatus
to 89 µm).
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4.1 Dry Film Thickness Device, It is an apparatus consist-
NOTE 2—For DFTmeasurements of films greater than 3.5 mils (89µm),
ing of either a manual or automated carbide-tipped drill that
but less than 63 mils (1600 µm), a 45° borer may be used in accordance
raises and lowers the boring tip perpendicular to the surface to
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
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unnecessary per 4.3.1 Method A.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
1.4 Measurements may be made on coil-coated sheet, cer-
Standards volume information, refer to the standard’s Document Summary page on
tain formed products, or on test panels.
the ASTM website.
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Withdrawn. The last approved version of this historical standard is referenced
on www.astm.org.
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This test method is under the jurisdiction of ASTM Committee D01 on Paint The sole source of supply of the dry film thickness device known to the
and Related Coatings, Materials, andApplications and is the direct responsibility of committee at this time is DJH Designs, 2366Wyecroft Rd., Unit D4, Oakville, Ont.,
Subcommittee D01.53 on Coil Coated Metal. Canada L6L 6M1. If you are aware of alternative suppliers, please provide this
Current edition approved May 10, 2003. Published June 2003. Originally information to ASTM International Headquarters. Your comments will receive
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approved in 1995. Last previous edition approved in 1999 as D5796 – 99. DOI: careful consideration at a meeting of the responsible technical committee, which
10.1520/D5796-03. you may attend.
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