ASTM C485-24

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: C485 − 24
Standard Test Method for
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Measuring Warpage of Ceramic Tile
This standard is issued under the fixed designation C485; 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 2. Referenced Documents
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2.1 ASTM Standards:
1.1 This test method covers procedures for measuring the
C242 Terminology of Ceramic Whitewares and Related
corner, diagonal, and edge warpages of ceramic tile.
Products
1.1.1 Tile Requirements for Corner, Diagonal, and Edge
2.2 ASTM Adjuncts:
Warpage Measurement Tile should be nominally flat, uniform
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Warpage Gage for Ceramic Tile
in overall thickness, smooth faced, and rectangular in shape,
including square.
3. Terminology
1.1.2 Tile Requirements for Corner Warpage Measurement
3.1 Definitions:
All facial edge dimensions equal to or greater than 2.36 in.
3.1.1 contact warpage device, n—consisting of a fixture that
(60 mm) in length.
has reference pins, contact gauges, and zero blank plates. The
1.1.3 Tile Requirements for Edge and Diagonal Warpage
device can be specific to a tile size or adjustable. Typically the
Measurement All facial edge dimensions equal to or greater
tile rests on the pins and the zero plane is fixed from these
than 2 in. (51 mm) in length.
contact points.
1.1.4 Trim Tile meeting the descriptions in 1.1.1 – 1.1.3
3.1.2 non-contact warpage device, n—a device that uses
except that only a part of the tile surface is flat. (Surface trim
some form of non-contact method to take measurements. An
tile should be treated as flat tile whenever possible.)
example would be laser measurement. These devices can use a
1.2 This test method is not applicable to tile having em- fixed reference plane (zero with flat blanks) or calculate a
theoretical reference plane.
bossed surfaces that are not flat, or that have a combination of
variable body thickness and an irregular face.
3.1.3 reference plane, n—the zero plane from which tile
planar deviations are measured.
1.3 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical 3.1.4 tile, n—see Definitions C242.
conversions to SI units that are provided for information only
3.1.5 warpage, n—curvature of a flat tile measured as
and are not considered standard.
deviation of the tile surface from a true plane along the edges,
at the corners, or the diagonals. The deviation is measured at
1.4 This standard does not purport to address all of the
the mid-length of an edge or diagonal, or at a corner, expressed
safety concerns, if any, associated with its use. It is the
as a percentage of the length of the edge, diagonal, or corner,
responsibility of the user of this standard to establish appro-
and called convex or concave with respect to the face of the
priate safety, health, and environmental practices and deter-
tile.
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
4.1 This method calculates the deviation of a ceramic tile
ization established in the Decision on Principles for the
from a flat plane. Measurements are made along the edges,
Development of International Standards, Guides and Recom-
diagonals, and corners of a tile. The deviation is expressed as
mendations issued by the World Trade Organization Technical
convex (positive) or concave (negative) warpage in relation to
Barriers to Trade (TBT) Committee.
the tile face.
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This method is under the jurisdiction of ASTM Committee C21 on Ceramic For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Whitewares and Related Productsand is the direct responsibility of Subcommittee contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
C21.06 on Ceramic Tile. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Feb. 1, 2024. Published February 2024. Originally the ASTM website.
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approved in 1961. Last previous edition approved in 2016 as C485 – 16. DOI: Three drawings showing construction details are available from ASTM
10.1520/C0485-24. Headquarters. Order ADJC0485.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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C485 − 24
FIG. 2 Apparatus as Shown in Fig. 1, Showing Arrangement of
Stem Ext
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