ASTM C1895-19

Standard Test Method for Determination of Mohs Scratch Hardness of Ceramic Tile

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 method covers the procedures to determine the Mohs scratch hardness of ceramic tile.  
1.2 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.  
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: Historical
• Publication Date: 30-Sep-2019
• ICS: 91.100.23 - Ceramic tiles
• Technical Committee: C21 - Ceramic Whitewares and Related Products
• Drafting Committee: C21.06 - Ceramic Tile

Relations

• Replaced By: ASTM C1895-20 - Standard Test Method for Determination of Mohs Scratch Hardness
• Effective Date: 01-Apr-2020
• Referred By: ASTM C1405-23 - Standard Specification for Glazed Brick (Single Fired, Brick Units)
• Effective Date: 01-Oct-2019

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: C1895 − 19
Standard Test Method for
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Determination of Mohs Scratch Hardness of Ceramic Tile
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.
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1. Scope 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
1.1 This method covers the procedures to determine the
specimen.
Mohs scratch hardness of ceramic tile.
3.3 Jeweler’s Loupe or other suitable magnification device.
1.2 Units—The values stated in inch-pound units are to be
regarded as standard. The values given in parentheses are 3.4 Sharpening stone or whetstone, a surface constructed of
mathematical conversions to SI units that are provided for suitable material to sharpen the hardness picks. Diamond
information only and are not considered standard. coated sharpening stones and sharpening stones constructed of
aluminum oxide or corundum have been known to work.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Reagents and Materials
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 4.1 Optional staining solution, such as methylene blue
mine the applicability of regulatory limitations prior to use.
solution, 1%.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard- 5. Test Specimens
ization established in the Decision on Principles for the
5.1 Number of Test Specimens—The test sample shall con-
Development of International Standards, Guides and Recom-
sist of at least one tile.
mendations issued by the World Trade Organization Technical
5.2 Size of Test Specimens—Test specimens up to6×6in.
Barriers to Trade (TBT) Committee.
(15 × 15 cm) shall remain uncut for testing. Specimens with
edges greater than 6in. may be reduced in size to no smaller
2. Significance and Use
than 6 in. (15 cm) for ease of handling.
2.1 Mohs scratch hardness is a useful tool for determining a
ceramic tile’s resistance to scratching. The resistance to
6. Preparation of Apparatus
scratching is determined based on a visual observation of the
6.1 Sharpening the Hardness Points—The hardness points
ceramictilesurfaceafteranattempttoscratchthesurfaceusing
may wear with use. Prior to testing, inspect the point of the
a pick of known hardness.
pickundermagnificationtoassurethatasharppointexistswith
3. Apparatus an even taper (see Fig. 3). Sharpening of the hardness points
2 may be necessary to remove any flat spots or imperfections.
3.1 Hardness Picks :
6.1.1 To sharpen the hardness point, remove the hardness
3.2 Hardness Pick Sled, a fixture used to hold the hardness
point from the hardness pick and place it into the chuck of an
pick at a 70 6 5° angle (see Fig. 1a, Fig. 1b, and Fig. 1c). The
electric drill.
sled shall be capable of applying a force of 7 6 0.5 lb. (3.2 6
6.1.2 Hold the hardness point against a sharpening stone at
0.2 kg) where the hardness point contacts the test specimen
approximately a 20° angle to the sharpening stone and use the
(see Fig. 2). This may be accomplished by adding an auxiliary
electric drill to rotate the hardness point (see Note 1).
NOTE 1—Excessive heat caused by friction may change the hardness of
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the pick.To prevent excessive heating, keep the sharpening stone wet and
ThistestmethodisunderthejurisdictionofASTMCommitteeC21onCeramic
Whitewares and Related Products and is the direct responsibility of Subcommittee do not attempt to sharpen for intervals greater than 10s. If additional
C21.06 on Ceramic Tile. sharpeningisnecessary,allowthehardnesspicktocoolpriortoadditional
Current edition approved Oct. 1, 2019. Published October 2019. DOI: 10.1520/
sharpening.
C1895-19.
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The sole source of supply of Hardness Picks is Mineralab, LLC, 2860 W. Live
Oak Drive, Prescott, AZ 86305. If you are aware of alternative suppliers, please
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provide this information toASTM International Headquarters. Your comments will The total weight necessary to apply the required force will vary based on the
receive careful consideration at a meeting of the responsible technical committee, overall weight of the sled and location of the weight on the sled, if an auxiliary
which you may attend. weight is used.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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C1895 − 19
Figure 1a – Side View
Figure 1b – Rear View
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