ASTM D3363-22

Standard Test Method for Film Hardness by Pencil Test

SIGNIFICANCE AND USE
5.1 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 using forced dried heat.  
5.2 This test method is convenient 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 manufacturer’s pencils as well as when different substrates 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.
Note 3: 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.  
5.3 This test method has been found to be useful in providing relative rankings for a series of coatings that exhibit significant differences in film hardness. Caution should be used when attempting to compare coatings of similar film hardness.  
5.4 This test method may not be appropriate for coatings applied to a wood or other softer substrate in which results may be more a function of substrate deformation than coating hardness.  
5.5 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 interested parties.
SCOPE
1.1 This test method covers a procedure for rapid, inexpensive determination of the film hardness of an organic coating on a metal or similarly hard 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

• Status: Published
• Publication Date: 31-May-2022
• ICS: 25.220.60 - Organic coatings
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.23 - Physical Properties of Applied Paint Films

Relations

• Refers: ASTM G171-03(2017) - Standard Test Method for Scratch Hardness of Materials Using a Diamond Stylus
• Effective Date: 01-Nov-2017
• Refers: ASTM D2197-13 - Standard Test Method for Adhesion of Organic Coatings by Scrape Adhesion
• Effective Date: 15-May-2013
• Refers: ASTM D5178-13 - Standard Test Method for Mar Resistance of Organic Coatings
• Effective Date: 15-May-2013
• Refers: ASTM D2197-10 - Standard Test Method for Adhesion of Organic Coatings by Scrape Adhesion
• Effective Date: 01-Jul-2010
• Refers: ASTM G171-03(2009)e2 - Standard Test Method for Scratch Hardness of Materials Using a Diamond Stylus
• Effective Date: 01-May-2009
• Refers: ASTM G171-03(2009)e1 - Standard Test Method for Scratch Hardness of Materials Using a Diamond Stylus
• Effective Date: 01-May-2009
• Refers: ASTM D5178-98(2008) - Standard Test Method for Mar Resistance of Organic Coatings
• Effective Date: 01-Jul-2008
• Refers: ASTM D2197-98(2004) - Standard Test Method for Adhesion of Organic Coatings by Scrape Adhesion
• Effective Date: 01-Jun-2004
• Refers: ASTM G171-03 - Standard Test Method for Scratch Hardness of Materials Using a Diamond Stylus
• Effective Date: 10-Jan-2003
• Refers: ASTM D5178-98(2002) - Standard Test Method for Mar Resistance of Organic Coatings
• Effective Date: 10-Feb-1998
• Refers: ASTM D2197-98(2002) - Standard Test Method for Adhesion of Organic Coatings by Scrape Adhesion
• Effective Date: 10-Feb-1998

Overview

ASTM D3363-22 is the Standard Test Method for Film Hardness by Pencil Test, developed by ASTM International. This widely-adopted standard provides a rapid and cost-effective procedure for evaluating the hardness of organic coatings applied to metal or similarly hard substrates. By utilizing pencils or drawing leads with defined hardness grades, the method allows the coatings industry to assess and compare the resistance of clear and pigmented films to damage such as scratching or gouging. This simple, practical technique supports both product development and quality control processes.

Key Topics

• Film Hardness Assessment: The pencil test determines how resistant a coating is to scratching (scratch hardness) or gouging (gouge hardness) by sliding pencils of increasing softness across the film surface.
• Pencil and Lead Selection: The hardness of the pencil leads used can significantly affect test results. Reproducibility improves when using leads from the same manufacturer and batch for all comparative testing.
• Substrate Considerations: The method is most suitable for hard substrates such as metal. Results may be unreliable on softer materials like wood, where substrate deformation may influence outcomes more than coating hardness.
• Laboratory Variability: Variations in pencil make or substrate can lead to different outcomes between laboratories. It is recommended to document the specific materials used and note deviations for consistent inter-lab comparisons.

Applications

The ASTM D3363-22 pencil hardness test is widely used in the coatings and finishes industry for:

• Development and Quality Control: Manufacturers of paints, varnishes, and other protective finishes use this test to evaluate the hardness of new formulations and to ensure consistency in production quality.
• Curing Assessment: The method provides a quick way to verify the curing status of organic coatings, particularly those cured by heat.
• Comparative Ranking: Enables clear differentiation of coatings with significant differences in film hardness, aiding in product selection and competitive benchmarking.
• Procurement and Regulatory Compliance: The test results can form part of purchase agreements between suppliers and buyers, provided all parties agree on the reference pencils and testing procedures.
• R&D and Troubleshooting: Research laboratories use the pencil hardness test to study the effect of formulation changes or environmental conditions on film hardness.

Related Standards

This standard is closely linked to other methods for evaluating the physical properties of organic coatings:

• ISO 15184: International equivalent for the pencil test, though not technically identical.
• ASTM D2197: Test method for adhesion of organic coatings by scrape adhesion.
• ASTM D5178: Test method for mar resistance of organic coatings.
• ASTM G171: Test method for scratch hardness using a diamond stylus.

Practical Value

By offering a straightforward, inexpensive, and swift means to assess coating hardness, ASTM D3363-22 supports both innovation and operational efficiency in the coatings sector. Its ease of use and reliability (when proper controls are in place) make it a staple for laboratories focused on paint, powder coating, industrial coating, and finish performance testing. For organizations engaged in coating application, procurement, or specification, adherence to this standard helps ensure that products meet required durability metrics and customer expectations.

Keywords: ASTM D3363, pencil hardness test, coating film hardness, organic coatings, quality control, paint hardness, scratch resistance, gouge resistance, standardized testing, film cure assessment.

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: D3363 − 22
Standard Test Method for
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:
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. Terminology
on a metal or similarly hard substrate in terms of drawing leads
3.1 Definitions of Terms Specific to This Standard:
or pencil leads of known hardness.
3.1.1 gouge hardness, n—the hardest pencil lead that will
1.2 This test method is similar in content (but not techni-
leavethefilmuncutforastrokelengthofatleast3mm( ⁄8 in.);
cally equivalent) to ISO 15184.
also referred to as pencil hardness.
NOTE 1—Other procedures are available to measure permanent defor-
3.1.2 scratch hardness, n—the hardest pencil lead that will
mation of organic coatings under the action of a single point (stylus tip)
not rupture or scratch the film.
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
4. Summary of Test Method
standard. The values given in parentheses are for information
4.1 A coated panel is placed on a firm horizontal surface.
only.
The pencil is held firmly against the film at a 45° angle (point
1.4 This standard does not purport to address all of the
awayfromtheoperator)andpushedawayfromtheoperatorfor
safety concerns, if any, associated with its use. It is the
a minimum of 6.5 mm ( ⁄4-in.) stroke. The process is started
responsibility of the user of this standard to establish appro-
with the hardest pencil and continued down the scale of
priate safety, health, and environmental practices and deter-
hardness to either of two end points: one, the pencil that will
mine the applicability of regulatory limitations prior to use.
not cut into or gouge the film (pencil hardness), or two, the
1.5 This international standard was developed in accor-
pencil that will not scratch the film (scratch hardness).
dance with internationally recognized principles on standard-
NOTE 2—A result in which the film coating is removed, revealing the
ization established in the Decision on Principles for the
substrate or previous coating layer if two or more coatings are present is
Development of International Standards, Guides and Recom-
considered a cut or gouge. A result in which the lead leaves a blemish or
mendations issued by the World Trade Organization Technical
defacement of the film coating, but does not reveal the substrate is
Barriers to Trade (TBT) Committee.
considered a scratch. A result in which the lead is transferred to the film
coating, but does not result in any damage is a pencil mark. See Fig. 1 and
2. Referenced Documents Fig. 2.
2.1 ASTM Standards:
5. Significance and Use
D2197 Test Method for Adhesion of Organic Coatings by
5.1 Pencil hardness measurements have been used by the
Scrape Adhesion
coatings industry for many years to determine the hardness of
D5178 Test Method for Mar Resistance of Organic Coatings
clear and pigmented organic coating films. This test method
G171 Test Method for Scratch Hardness of Materials Using
has also been used to determine the cure of these coatings,
a Diamond Stylus
especially when using forced dried heat.
5.2 This test method is convenient in developmental work
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and in production control testing in a single laboratory. It
and Related Coatings, Materials, andApplications and is the direct responsibility of
should be recognized that the results obtained may vary
Subcommittee D01.23 on Physical Properties of Applied Paint Films.
CurrenteditionapprovedJune1,2022.PublishedJuly2022.Originallyapproved
between different laboratories when different manufacturer’s
in 1974. Last previous edition approved in 2020 as D3363 – 20. DOI: 10.1520/
pencils as well as when different substrates are used. To
D3363-22.
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 Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 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
D3363 − 22
FIG. 1 Representation of Gouge vs. Scratch
FIG. 2 Typical Example of Pencil Test
improve test result reproducibility for a specific group of tests, 5.5 If this test method is used as a basis for purchase
it is recommended to utilize drawing leads or pencils made by agreement, maximum precision will be achieved if a given set
the same manufacturer and from the same batch. If drawing of referee pencils be agreed upon between the interested
leadsorpencilsfromthesamemanufacturerandfromthesame parties.
batch are not available at the time of subsequent evaluations, it
shall be noted on the test report. 6. Apparatus
NOTE 3—Using leads or pencils made by different manufacturers or 6.1 A set of drawing leads or wood pencils (see 5.2). The
from the same manufacturer but different production batches, may result
leads must be nominal 2 mm diameter and meet the following
in significant variation for leads within the same pencil hardness scale.
scale of hardness:
5.3 This test method has been found to be useful in
6B25B24B23B22B2B2HB2F2H22H23H24H25H26H
providing relative rankings for a series of coatings that exhibit
Softer Harder
significant differences in film hardness. Caution should be used
(1)
when attempting to compare coatings of similar film hardness.
The difference between two adjacent leads shall be consid-
5.4 This test method may not be appropriate for coatings
ered one unit of hardness.
appliedtoawoodorothersoftersubstrateinwhichresultsmay
be more a function of substrate deformation than coating
NOTE 4—Drawing leads or wood pencils in the range of 9B to 9H are
hardness. acceptable to use.
D3363 − 22
6.1.1 A device, with two wheels, that holds the pencil at a
45° angle and allows the tip of the pencil to exert a consistent
force during the test may be used if agreed upon by the
FIG. 3 View of Wood Pencil
interestedparties.Thisdeviceshallnotbeusedforsofter
...

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: D3363 − 20 D3363 − 22
Standard Test Method for
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*
1.1 This test method covers a procedure for rapid, inexpensive determination of the film hardness of an organic coating on a metal
or similarly hard 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.
2. Referenced Documents
2.1 ASTM Standards:
D2197 Test Method for Adhesion of Organic Coatings by Scrape Adhesion
D5178 Test Method for Mar Resistance of Organic Coatings
G171 Test Method for Scratch Hardness of Materials Using a Diamond Stylus
2.2 Other Standards:
ISO 15184 Determination of film hardness by pencil test.test
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
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 D01.23 on Physical Properties of Applied Paint Films.
Current edition approved Sept. 1, 2020June 1, 2022. Published September 2020July 2022. Originally approved in 1974. Last previous edition approved in 20112020 as
ɛ2
D3363 – 05 (2011)D3363 – 20. which was withdrawn in May 2020 and reinstated in September 2020. DOI: 10.1520/D3363-20.DOI: 10.1520/D3363-22.
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.
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
D3363 − 22
3.1.1 gouge hardness, n—the hardest pencil lead that will leave the film uncut for a stroke length of at least 3 mm ( ⁄8 in.); also
referred to as pencil hardness.
3.1.2 scratch hardness, n—the hardest pencil lead that will not rupture or scratch the film.
4. Summary of Test Method
4.1 A coated panel is placed on a firm horizontal surface. The pencil is held firmly against the film at a 45° angle (point away from
the operator) and pushed away from the operator in a 6.5-mm for a minimum of 6.5 mm ( ⁄4-in.) stroke. The process is started with
the hardest pencil and continued down the scale of hardness to either of two end points: one, the pencil that will not cut into or
gouge the film (pencil hardness), or two, the pencil that will not scratch the film (scratch hardness).
NOTE 2—A result in which the film coating is removed, revealing the substrate or previous coating layer if two or more coatings are present is considered
a cut or gouge. A result in which the lead leaves a blemish or defacement of the film coating, but does not reveal the substrate is considered a scratch.
A result in which the lead is transferred to the film coating, but does not result in any damage is a pencil mark. See Fig. 1 and Fig. 2.
5. Significance and Use
5.1 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 using
forced dried using heat.
5.2 This test method is especially useful convenient 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 manufacturer’s pencils as
well as panels when different substrates 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 3—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.
5.3 This test method has been found to be useful in providing relative rankings for a series of coatings that exhibit significant
differences in film hardness. Caution should be used when attempting to compare coatings of similar film hardness.
5.4 This test method may not be appropriate for coatings applied to a wood or other softer substrate in which results may be more
a function of substrate deformation than coating hardness.
5.5 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.interested parties.
FIG. 1 Representation of Gouge vs. Scratch
D3363 − 22
FIG. 2 Typical Example of Pencil Test
6. Apparatus
6.1 A set of drawing leads (preferred) or wood pencils (see 4.25.2). The leads must be nominal 2 mm diameter and meet the
following scale of hardness:
6B25B24B23B22B2B2HB2F2H22H23H24H25H26H
(1)
Softer Harder
The difference between two adjacent leads shall be considered one unit of hardness.
NOTE 4—Drawing leads or wood pencils in the range of 9B to 9H are acceptable to use.
6.1.1 A device, with two wheels, that holds the pencil at a 45° angle and allows the tip of the pencil to exert a consistent force
during the test may be used if agreed upon by the interested parties. This device shall not be used for softer leads, if the edge of
the lead crumbles under the weight of the device. The device may need additional applied pressure to crumble hard leads.
6.2 Mechanical Lead Holder, for drawing leads if used.used (see Fig. 4).
6.3 Mechanical Sharpener, draftsman-type, modified draftsman-type which will remove the wood only, leaving the cylindrical
pencil lead intact, is h
...