ASTM D3363-20
(Test Method)Standard Test Method for Film Hardness by Pencil Test
Standard Test Method for Film Hardness by Pencil Test
SIGNIFICANCE AND USE
4.1 Pencil hardness measurements have been used by the coatings industry for many years to determine the hardness of clear and pigmented organic coating films. This test method has also been used to determine the cure of these coatings, especially when forced dried using heat.
4.2 This test method is especially useful in developmental work and in production control testing in a single laboratory. It should be recognized that the results obtained may vary between different laboratories when different pencils as well as panels are used. To improve test result reproducibility for a specific group of tests, it is recommended to utilize drawing leads or pencils made by the same manufacturer and from the same batch. If drawing leads or pencils from the same manufacturer and from the same batch are not available at the time of subsequent evaluations, it shall be noted on the test report. For all tests, the manufacturer and lot number of the drawing leads or pencils shall be reported.
Note 2: Using leads or pencils made by different manufacturers or from the same manufacturer but different production batches, may result in significant variation for leads within the same pencil hardness scale.
4.3 If this test method is used as a basis for purchase agreement, maximum precision will be achieved if a given set of referee pencils be agreed upon between the purchaser and the seller.
SCOPE
1.1 This test method covers a procedure for rapid, inexpensive determination of the film hardness of an organic coating on a substrate in terms of drawing leads or pencil leads of known hardness.
1.2 This test method is similar in content (but not technically equivalent) to ISO 15184.
Note 1: Other procedures are available to measure permanent deformation of organic coatings under the action of a single point (stylus tip) including but not limited to Test Methods D2197, D5178, and G171.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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
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: D3363 − 20
Standard Test Method for
1
Film Hardness by Pencil Test
This standard is issued under the fixed designation D3363; 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 U.S. Department of Defense.
1. Scope* 2.2 Other Standards:
3
ISO 15184 Determination of film hardness by pencil test.
1.1 This test method covers a procedure for rapid, inexpen-
sive determination of the film hardness of an organic coating
3. Summary of Test Method
on a substrate in terms of drawing leads or pencil leads of
3.1 A coated panel is placed on a firm horizontal surface.
known hardness.
The pencil is held firmly against the film at a 45° angle (point
1.2 This test method is similar in content (but not techni-
away from the operator) and pushed away from the operator in
cally equivalent) to ISO 15184.
1
a6.5-mm( ⁄4-in.)stroke.Theprocessisstartedwiththehardest
NOTE 1—Other procedures are available to measure permanent defor-
pencil and continued down the scale of hardness to either of
mation of organic coatings under the action of a single point (stylus tip)
two end points: one, the pencil that will not cut into or gouge
including but not limited to Test Methods D2197, D5178, and G171.
the film (pencil hardness), or two, the pencil that will not
1.3 The values stated in SI units are to be regarded as the
scratch the film (scratch hardness).
standard. The values given in parentheses are for information
only.
4. Significance and Use
1.4 This standard does not purport to address all of the
4.1 Pencil hardness measurements have been used by the
safety concerns, if any, associated with its use. It is the
coatings industry for many years to determine the hardness of
responsibility of the user of this standard to establish appro-
clear and pigmented organic coating films. This test method
priate safety, health, and environmental practices and deter-
has also been used to determine the cure of these coatings,
mine the applicability of regulatory limitations prior to use.
especially when forced dried using heat.
1.5 This international standard was developed in accor-
4.2 This test method is especially useful in developmental
dance with internationally recognized principles on standard-
work and in production control testing in a single laboratory. It
ization established in the Decision on Principles for the
should be recognized that the results obtained may vary
Development of International Standards, Guides and Recom-
between different laboratories when different pencils as well as
mendations issued by the World Trade Organization Technical
panels are used. To improve test result reproducibility for a
Barriers to Trade (TBT) Committee.
specific group of tests, it is recommended to utilize drawing
2. Referenced Documents
leads or pencils made by the same manufacturer and from the
2 same batch. If drawing leads or pencils from the same
2.1 ASTM Standards:
manufacturer and from the same batch are not available at the
D2197 Test Method for Adhesion of Organic Coatings by
time of subsequent evaluations, it shall be noted on the test
Scrape Adhesion
report. For all tests, the manufacturer and lot number of the
D5178 Test Method for Mar Resistance of Organic Coatings
drawing leads or pencils shall be reported.
G171 Test Method for Scratch Hardness of Materials Using
a Diamond Stylus
NOTE 2—Using leads or pencils made by different manufacturers or
from the same manufacturer but different production batches, may result
1 in significant variation for leads within the same pencil hardness scale.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
4.3 If this test method is used as a basis for purchase
Subcommittee D01.23 on Physical Properties of Applied Paint Films.
agreement, maximum precision will be achieved if a given set
Current edition approved Sept. 1, 2020. Published September 2020. Originally
ɛ2
of referee pencils be agreed upon between the purchaser and
approved in 1974. Last previous edition approved in 2011 as D3363 – 05 (2011)
which was withdrawn in May 2020 and reinstated in September 2020. DOI:
the seller.
10.1520/D3363-20.
2
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
3
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New
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