ASTM C1895-20

Standard Test Method for Determination of Mohs Scratch Hardness

SIGNIFICANCE AND USE
2.1 Mohs scratch hardness is a useful tool for determining a ceramic tile’s resistance to scratching. The resistance to scratching is determined based on a visual observation of the ceramic tile surface after an attempt to scratch the surface using a pick of known hardness.
SCOPE
1.1 This test method covers the procedures to determine the Mohs scratch hardness of ceramic tile, glass tile, and other hard surfaces.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 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.  
1.4 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-Mar-2020
• ICS: 91.100.23 - Ceramic tiles
• Technical Committee: C21 - Ceramic Whitewares and Related Products
• Drafting Committee: C21.06 - Ceramic Tile

Relations

• Replaces: ASTM C1895-19 - Standard Test Method for Determination of Mohs Scratch Hardness of Ceramic Tile
• Effective Date: 01-Apr-2020
• Referred By: ASTM C1405-23 - Standard Specification for Glazed Brick (Single Fired, Brick Units)
• Effective Date: 01-Apr-2020

Overview

ASTM C1895-20: Standard Test Method for Determination of Mohs Scratch Hardness is an internationally recognized ASTM standard that describes a test method for evaluating the scratch hardness of ceramic tile, glass tile, and other hard surfaces. Mohs scratch hardness is a critical property for materials used in flooring, wall cladding, and architectural applications, as it determines their resistance to abrasion and wear. The method involves attempting to scratch a material with a pick of known hardness and visually inspecting the surface for scratches. This standard establishes uniform procedures to ensure reliable, repeatable results across laboratories and manufacturers worldwide.

Key Topics

• Purpose: The test determines how well a surface resists scratching, aiding in material selection for durability and performance.
• Scope: Applies to ceramic tile, glass tile, and comparable hard surfaces. The method is suitable for both inch-pound and SI unit systems, though inch-pound units are considered standard.
• Significance: Ensures product quality by quantifying scratch resistance, which is vital for consumer confidence and compliance with industry requirements.
• Test Procedure: Involves:
  • Using hardness picks of known values.
  • Fixing the pick at a set angle and dragging it across the test specimen under controlled force.
  • Inspecting the surface visually or with magnification to determine the presence of scratches.
• Safety and Responsibility: The standard highlights the need for users to establish appropriate safety, health, and environmental practices when conducting the test.

Applications

• Quality Control: Manufacturers use ASTM C1895-20 in production and post-production to assess the scratch hardness of tiles and ensure compliance with industry standards.
• Research and Development: Laboratories apply this test method to compare new formulations or surface treatments, optimizing products for high-wear environments.
• Specification Compliance: Specifiers and architects reference Mohs hardness results when selecting materials for commercial, institutional, or residential construction projects, ensuring surfaces will withstand daily wear.
• Market Differentiation: Suppliers utilize test results to demonstrate their product’s performance, supporting marketing claims regarding durability and scratch resistance.

Related Standards

• ASTM C1026: Standard Test Method for Measuring the Freeze-Thaw Resistance of Ceramic Tile.
• ASTM C373: Standard Test Method for Water Absorption, Bulk Density, Apparent Porosity, and Apparent Specific Gravity of Fired Whiteware Products.
• ISO 10545-7: International standard related to the determination of surface abrasion resistance of glazed ceramic tiles.
• ASTM C650: Standard Test Method for Resistance of Ceramic Tile to Chemical Substances.

Conclusion

ASTM C1895-20 provides a systematic approach to determine the Mohs scratch hardness of ceramic and glass tile, supporting consistent product quality and reliable performance information for manufacturers and specifiers. As tile durability is a key consideration in architectural and interior design, this standard plays a central role in selecting materials fit for purpose in both commercial and residential settings. Adherence to ASTM C1895-20 helps ensure end-user satisfaction and regulatory compliance in diverse markets.

Keywords: ASTM C1895-20, Mohs scratch hardness, ceramic tile, glass tile, surface hardness test, ASTM standard, abrasion resistance, tile quality, flooring standards, building materials testing.

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: C1895 − 20
Standard Test Method for
Determination of Mohs Scratch Hardness
This standard is issued under the fixed designation C1895; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 0.2 kg) where the hardness point contacts the test specimen
(see Fig. 2). This may be accomplished by adding an auxiliary
1.1 This test method covers the procedures to determine the
weight to the top of the sled. The sled shall be equipped with
Mohsscratchhardnessofceramictile,glasstile,andotherhard
a handle to aid in pulling the hardness pick across the test
surfaces.
specimen.
1.2 The values stated in inch-pound units are to be regarded
NOTE 1—The total weight necessary to apply the required force will
as standard. The values given in parentheses are mathematical
vary based on the overall weight of the sled and location of the weight on
conversions to SI units that are provided for information only
the sled, if an auxiliary weight is used.
and are not considered standard.
3.3 Jeweler’s Loupe or Other Suitable Magnification De-
1.3 This standard does not purport to address all of the
vice.
safety concerns, if any, associated with its use. It is the
3.4 Sharpening Stone or Whetstone—A surface constructed
responsibility of the user of this standard to establish appro-
of suitable material to sharpen the hardness picks. Diamond
priate safety, health, and environmental practices and deter-
coated sharpening stones and sharpening stones constructed of
mine the applicability of regulatory limitations prior to use.
aluminum oxide or corundum have been known to work.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4. Reagents and Materials
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4.1 Optional staining solution, such as methylene blue
mendations issued by the World Trade Organization Technical
solution, 1%.
Barriers to Trade (TBT) Committee.
5. Test Specimens
2. Significance and Use
5.1 Number of Test Specimens—The test sample shall con-
2.1 Mohs scratch hardness is a useful tool for determining a
sist of at least one tile.
ceramic tile’s resistance to scratching. The resistance to
5.2 Size of Test Specimens—Test specimens up to6×6in.
scratching is determined based on a visual observation of the
(15 × 15 cm) shall remain uncut for testing. Specimens with
ceramictilesurfaceafteranattempttoscratchthesurfaceusing
edges greater than 6in. may be reduced in size to no smaller
a pick of known hardness.
than 6 in. (15 cm) for ease of handling.
3. Apparatus
6. Preparation of Apparatus
3.1 Hardness Picks:
6.1 Sharpening Hardness Points—The hardness points may
3.2 Hardness Pick Sled—Afixtureusedtoholdthehardness
wear with use. Prior to testing, inspect the point of the pick
pick at a 70 6 5° angle (see Fig. 1a, Fig. 1b, and Fig. 1c). The
under magnification to assure that a sharp point exists with an
sled shall be capable of applying a force of 7 6 0.5 lb. (3.2 6
even taper (see Fig. 3). Sharpening of the hardness points may
be necessary to remove any flat spots or imperfections.
6.1.1 To sharpen the hardness point, remove the hardness
ThistestmethodisunderthejurisdictionofASTMCommitteeC21onCeramic
Whitewares and Related Products and is the direct responsibility of Subcommittee point from the hardness pick and place it into the chuck of an
C21.06 on Ceramic Tile.
electric drill.
Current edition approved April 1, 2020. Published April 2020. Originally
6.1.2 Hold the hardness point against a sharpening stone at
approved in 2019. Last previous edition approved in 2019 as C1895–19. DOI:
approximately a 20° angle to the sharpening stone and use the
10.1520/C1895-20.
The sole source of supply of the apparatus known to the committee at this time
electric drill to rotate the hardness point (see Note 2).
is Mineralab, LLC, 2860 W. Live Oak Drive, Prescott,AZ 86305. If you are aware
NOTE 2—Excessive heat caused by friction may change the hardness of
of alternative suppliers, please provide this information to ASTM International
Headquarters.Your comments will receive careful consideration at a meeting of the the pick.To prevent excessive heating, keep the sharpening stone wet and
responsible technical committee, which you may attend. do not attempt to sharpen for intervals greater than 10s. If additional
Copyright © ASTM Internati
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Uncomposed text in Xyvision Standard Format Page 1
C189519C189520Standard
Test Method forDetermination of Mohs Scratch Hardness
of Ceramic Tile1This
standard is issued under the fixed designation C1895; 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. Scope
This test method covers
the procedures to determine the Mohs scratch hardness of ceramic tile.tile,
glass tile, and other hard surfaces.Units—The
values stated in inch-pound units are to be regarded as standard. The values
given in parentheses are mathematical conversions to SI units that are provided
for information only and are not considered standard.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.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.Significance
and UseMohs scratch hardness
is a useful tool for determining a ceramic tile’s resistance to scratching.
The resistance to scratching is determined based on a visual observation of
the ceramic tile surface after an attempt to scratch the surface using a pick
of known hardness. ApparatusHardness
Picks2: Hardness
Picks:2Hardness
Pick Sled—Hardness Pick Sled, a A fixture
used to hold the hardness pick at a 70 6 5° angle (see Fig.
1a, Fig.
1b, and Fig. 1c).
The sled shall be capable of applying a force of 7 6 0.5 lb. (3.2 6 0.2 kg)
where the hardness point contacts the test specimen (see Fig.
2). This may be accomplished by adding
an auxiliary weight to the top of the sled. The sled shall
be equipped with a handle to aid in pulling the hardness pick across the test
specimen.Note 1The
total weight necessary to apply the required force will vary based on the overall
weight of the sled and location of the weight on the sled, if an auxiliary weight
is used.Jeweler’s
Loupe or other suitable magnification device.Jeweler’s
Loupe or Other Suitable Magnification Device. Sharpening
Stone or Whetstone—Sharpening stone or whetstone, a A
surface constructed of suitable material to sharpen the hardness picks. Diamond

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