ASTM D6677-18(2022)
(Test Method)Standard Test Method for Evaluating Adhesion by Knife
Standard Test Method for Evaluating Adhesion by Knife
SIGNIFICANCE AND USE
4.1 Coatings, to perform satisfactorily, must adhere to the substrates on which they are applied. This test method has been found useful as a simple means of assessing the adhesion of coatings. Although this method is a qualitative (subjective) test it has been used in industry for many years and can provide valuable information.
4.2 Other adhesion test methods may be useful in obtaining quantitative results. See Test Methods D2197, D3359, D4541, and D7234.
4.3 The Performance Evaluation Scale (see Table 1) is based on both the degree of difficulty to remove the coating from the substrate and the size of removed coating chip.
4.4 This test method does not have a known correlation to other adhesion test methods (pull-off, tape, etc.).
4.5 A coating that has a high degree of cohesive strength may appear to have worse adhesion than one that is brittle and hence fractures easily when probed.
4.6 This method is not to be used on overly thick coatings, that is, those which cannot be cut to the substrate with a utility knife in one stroke.
SCOPE
1.1 This test method covers the procedure for assessing the adhesion of coating films to substrate by using a knife.
1.2 This test method is used to establish whether the adhesion of a coating to a substrate or to another coating (in multi-coat systems) is at a generally adequate level.
Note 1: The term “substrate” relates to the basic surface on which a coating adheres (may be steel, concrete, etc. or other coating).
1.3 This method can be used in the laboratory and field.
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 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
Relations
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: D6677 − 18 (Reapproved 2022)
Standard Test Method for
Evaluating Adhesion by Knife
This standard is issued under the fixed designation D6677; 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 D4541 Test Method for Pull-Off Strength of Coatings Using
Portable Adhesion Testers
1.1 This test method covers the procedure for assessing the
D6132 Test Method for Nondestructive Measurement of Dry
adhesion of coating films to substrate by using a knife.
Film Thickness of Applied Organic Coatings Using an
1.2 This test method is used to establish whether the
Ultrasonic Coating Thickness Gage
adhesion of a coating to a substrate or to another coating (in
D7091 Practice for Nondestructive Measurement of Dry
multi-coat systems) is at a generally adequate level.
Film Thickness of Nonmagnetic Coatings Applied to
Ferrous Metals and Nonmagnetic, Nonconductive Coat-
NOTE 1—The term “substrate” relates to the basic surface on which a
coating adheres (may be steel, concrete, etc. or other coating).
ings Applied to Non-Ferrous Metals
D7234 Test Method for Pull-OffAdhesion Strength of Coat-
1.3 This method can be used in the laboratory and field.
ings on Concrete Using Portable Pull-Off Adhesion Tes-
1.4 The values stated in SI units are to be regarded as the
ters
standard. The values given in parentheses are for information
only. 3. Summary of Test Method
1.5 This standard does not purport to address all of the 3.1 Adhesion is determined by scribing an “X” into the
safety concerns, if any, associated with its use. It is the
coating film to the substrate and by lifting the coating with the
responsibility of the user of this standard to establish appro- point of a utility knife. Adhesion is evaluated qualitatively on
priate safety, health, and environmental practices and deter-
a 0 to 10 scale.
mine the applicability of regulatory limitations prior to use.
4. Significance and Use
1.6 This international standard was developed in accor-
4.1 Coatings, to perform satisfactorily, must adhere to the
dance with internationally recognized principles on standard-
substrates on which they are applied.This test method has been
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- found useful as a simple means of assessing the adhesion of
coatings.Although this method is a qualitative (subjective) test
mendations issued by the World Trade Organization Technical
it has been used in industry for many years and can provide
Barriers to Trade (TBT) Committee.
valuable information.
2. Referenced Documents
4.2 Other adhesion test methods may be useful in obtaining
2.1 ASTM Standards: quantitative results. See Test Methods D2197, D3359, D4541,
and D7234.
D2197 Test Method for Adhesion of Organic Coatings by
Scrape Adhesion
4.3 The Performance Evaluation Scale (see Table 1)is
D3359 Test Methods for Rating Adhesion by Tape Test
based on both the degree of difficulty to remove the coating
D4138 Practices for Measurement of Dry Film Thickness of
from the substrate and the size of removed coating chip.
Protective Coating Systems by Destructive, Cross-
4.4 This test method does not have a known correlation to
Sectioning Means
other adhesion test methods (pull-off, tape, etc.).
4.5 A coating that has a high degree of cohesive strength
may appear to have worse adhesion than one that is brittle and
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
hence fractures easily when probed.
Subcommittee D01.46 on Industrial Protective Coatings.
4.6 This method is not to be used on overly thick coatings,
Current edition approved Dec. 1, 2022. Published December 2022. Originally
approved in 2001. Last previous edition approved in 2018 as D6677 – 18. DOI:
that is, those which cannot be cut to the substrate with a utility
10.1520/D6677-18R22.
knife in one stroke.
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
5. Apparatus and Materials
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.1 Cutting Tool—Sharp utility knife.
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D6677 − 18 (2022)
TABLE 1 Rating System
7.3
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