ASTM F970-22

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: F970 − 17 F970 − 22
Standard Test Method for
Measuring Recovery Properties of Floor Coverings after
Static Loading
This standard is issued under the fixed designation F970; 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
1.1 This test method is intended for use in determining the recovery properties of uninstalled resilient floor covering after
long-term indentation test, 24 h under the load specified in the detail specification. The reported value, residual indentation, is the
depth of the depression remaining 24 h after removal of the specified load.
1.2 This test method is intended to evaluate ex-factory floor covering and is not intended to evaluate the performance of installed
floor coverings.
1.3 This test method is not intended for use in evaluating the long-term indentation resistance or recovery properties, or both, of
resilient floor coverings at loads above those listed in the Precision and Bias statement as described in Section 10.
1.3.1 Testing at loads above 250 psi is outside the scope of this test method.
1.4 Testing with any other indentor plate other than the exact plates listed in Section 4 is outside the scope of this test method.
1.5 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.
1.6 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.
1.7 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:
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
F386 Test Method for Thickness of Resilient Flooring Materials Having Flat Surfaces
F387 Test Method for Measuring Thickness of Resilient Floor Covering With Foam Layer
This test method is under the jurisdiction of ASTM Committee F06 on Resilient Floor Coverings and is the direct responsibility of Subcommittee F06.20 on Test Methods.
Current edition approved May 1, 2017Oct. 1, 2022. Published May 2017October 2022. Originally approved in 1987. Last previous edition approved in 20152017 as
F970–15.–17. DOI: 10.1520/F0970–17.10.1520/F0970–22.
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 Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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F970 − 22
F1914 Test Methods for Short-Term Indentation and Residual Indentation of Resilient Floor Covering
3. Significance and Use
3.1 This test method is a meaningful test for determining the indentation recovery properties of uninstalled resilient floor
covering.
3.2 This test method is intended solely for the purpose of determining compliance, where applicable, with static load requirements
set forth in resilient flooring product specifications under the jurisdiction of ASTM Committee F06 on Resilient Floor Coverings.
3.3 As testing is conducted on uninstalled flooring, results are not an indicator of the floor covering’s installed performance.
4. Apparatus
4.1 The following apparatus shall be used:
4.2 Conditioning Room, providing the standard laboratory atmosphere of 50 6 5 %50 % 6 5 % relative humidity at a temperature
of 73.4 6 3.6°F (23 6 2.0°C).73.4 °F 6 3.6 °F (23 °C 6 2.0 °C).
4.3 Indentation Machine, as described in Section 12 and pictured in Fig. 2 of Test Method F1914.
4.4 Indentor Plates, each constructed of a piece of 2-in.2 in. (50.8 mm) square stainless steel, 0.240 6 0.005 in. (6.1 6 0.1 mm)
0.240 in. 6 0.005 in. (6.1 mm 6 0.1 mm) thick, with one side turned to 1.125 in. (28.6 mm) in diameter (one square inch area)
to depth of 0.150 in. (3.8 mm) (see Fig. 1).
4.5 Dial Micrometer, as described in Test Method F386 when measuring resilient floor coverings containing a foam layer as part
of the construction or as described in Test Method F387 when measuring all other resilient floor coverings.
4.6 Template of Poly(methyl Methacrylate) (PMMA), or of other transparent material, 22 in. by 2 in. (50.8(50.8 mm by 50.8 mm)
with round scratch line centered on the template that is 1.125 in. (28.58 mm) in diameter, defining the test area, and with a ⁄2 in.
(12.7 mm) diameter hole at the center of the template to draw a circle on the specimen where thickness will be measured.
NOTE 1—All dimensions are in inches. Tolerance is 60.005 in. (60.1 mm).
Metric Equivalents:
Inches Millimetres
2.000 50.8
1.125 28.6
0.240 6.1
0.150 3.8
0.090 2.3
FIG. 1 Indentor Plates for Static Load Limit Test
For additional information, see Resilient Floor Covering Institute (RFCI) document, Static Limit Testing of Resilient Flooring Products, available from RFCI, 115 Broad
Street, Suite 201, La Grange, GA 30240, www.rfci.com.
F970 − 22
4.7 Die, 22 in. by 2 in. (50.8(50.8 mm by 50.8 mm) and press, papercutter, or equivalent to cut specimens to 22 in. by 2 in. size
(50.8(50.8 mm by 50.8 mm).
4.8 Optional—Open box without spring clips for 22 in. by 2 in. (50.8(50.8 mm by 50.8 mm) photographic slides, or equivalent,
to separate specimens during conditioning and recovery periods.
5. Sampling, Test Specimens and Test Units
5.1 The specimens shall be 22 in. by 2 in. (50.8(50.8 mm by 50.8 mm). The test unit shall consist of three specimens.
5.2 The central one square inch test area of each specimen should be free of mortar lines or other embossing lines, if possible.
If not possible, the largest flat, raised area should be centered on the specimen.
5.3 If the sample is nubble embossed, the specimen should be cut so that a nub is at the center of the specimen where the specimen
will be measured.
5.4 A circle slightly larger than the 0.250 in. (6.35 mm) diameter foot of the thickness gauge (4.5) is drawn on the wear layer at
the center of the specimen, using the PMMA template (4.6), to ensure that thickness measurements are made at the same spot.
6. Conditioning
6.1 Condition the test unit at least 16 h at 73.4 6 3.6°F (23.073.4 °F 6 3.6 °F (23.0 °C 6 2.0°C)2.0 °C) and
50 6 5 %50 % 6 5 % relative humidity and test in the same environment.
7. Procedures
7.1 Measure the initial thickness of each specimen, wear layer up, at the center of the specimen using the dial micrometer. Record
the value to the nearest 0.001 in. (0.025 mm) as T .
7.2 Place the 22 in. by 2 in. (50.8(50.8 mm by 50.8 mm) indentor plate on top of the 22 in. by 2 in. (50.8(50.8
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