ASTM D2821-19

Standard Test Method for Measuring the Relative Stiffness of Leather by Means of a Torsional Wire Apparatus

SIGNIFICANCE AND USE
3.1 This test method is designed to measure the apparent torsional modulus3 of a leather specimen. Experience has shown that the torsion modulus of leather is directly related to the characteristic known as stiffness when felt in a glove.4
SCOPE
1.1 This test method describes the use of a torsional apparatus for measuring the relative stiffness of gloving leathers. This test method does not apply to wet blue.  
1.2 The values stated in SI units are to be regarded as the standard. The values shown in parentheses are provided for information only.  
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-2019
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.04 - Apparel

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: D2821 − 19
Standard Test Method for
Measuring the Relative Stiffness of Leather by Means of a
1
Torsional Wire Apparatus
This standard is issued under the fixed designation D2821; 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 3. Significance and Use
3.1 This test method is designed to measure the apparent
1.1 This test method describes the use of a torsional
3
torsional modulus of a leather specimen. Experience has
apparatus for measuring the relative stiffness of gloving leath-
shown that the torsion modulus of leather is directly related to
ers. This test method does not apply to wet blue.
4
the characteristic known as stiffness when felt in a glove.
1.2 The values stated in SI units are to be regarded as the
standard. The values shown in parentheses are provided for 4. Apparatus
5
information only.
4.1 Torsion Apparatus — The torsional apparatus, Fig. 1,
shall consist of a torsion head, A, capable of being turned
1.3 This standard does not purport to address all of the
through a complete circle in a plane normal to the torsion wire,
safety concerns, if any, associated with its use. It is the
N. The torsion head is equipped with an upper dial or
responsibility of the user of this standard to establish appro-
protractor, K, graduated from 0 to 360° in increments not
priate safety, health, and environmental practices and deter-
greater than 5°, and a fixed index pointer, L. The protractor is
mine the applicability of regulatory limitations prior to use.
attached to the torsion head by means of a friction bearing to
1.4 This international standard was developed in accor-
permit movement for adjusting the zero point. The top of the
dance with internationally recognized principles on standard-
torsion wire is attached to the torsion head at knob H by set
ization established in the Decision on Principles for the
screwBandpassesthroughthecenterofalooselyfittingsleeve
Development of International Standards, Guides and Recom-
gripped by the friction bearing. The torsion head support
mendations issued by the World Trade Organization Technical
carries a split bearing which can be activated by knob G, thus
Barriers to Trade (TBT) Committee.
locking the sleeve carrying the wire and permitting adjustment
2. Referenced Documents
3
2
This test method is similar to Test Method D1053. The original apparatus was
2.1 ASTM Standards:
described by Williamson, I., British Plastics, Vol 23, 1950, pp 87-90, 102; and
D1053 Test Methods for Rubber Property—Stiffening at
typical examples of the results of its use on leather were given in a paper by
LowTemperatures: Flexible Polymers and Coated Fabrics Witnauer, L. PA, and Palm, W.E., Journal, American Leather Chemist’s Assn.,
JALCA, Vol 59, 1964, pp. 246-258.
D1610 Practice for Conditioning Leather and Leather Prod-
4
Gloves were made from the neck and butt areas of cattlehide work-glove
ucts for Testing
leather selected for 3° of softness varying from soft to firm.These were ranked from
softest to firmest by 20 individuals. Since there was some overlapping of rank as
assigned by individual observers, the final rank was assigned according to highest
numberofselections.Specimensofleathercutfromthesidesintheareafromwhich
1
This test method is under the jurisdiction ofASTM Committee D31 on Leather each glove was cut were tested for stiffness according to this test method.At 90° of
and is the direct responsibility of Subcommittee D31.04 on Apparel. This test twist, the stiffness values gave a ranking similar to that obtained by feel. Specimens
method was developed in cooperation with the American Leather Chemists Assn. cut parallel to the backbone gave more consistent ranking than specimens cut
Current edition approved April 1, 2019. Published May 2019. Originally perpendicular to the backbone. This undoubtedly reflects the fact that work gloves
approved in 1969 as D2821 – 69T. Last previous edition approved in 2014 as are cut from a side with the fingers parallel to the backbone.
5
D2821 – 14. DOI: 10.1520/D2821-19. The sole source of supply of the apparatus known to the committee at this time
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or is Taber Industries, 455 Bryant Street, North Tonawanda, NY, 14120. If you are
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM awar
...

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: D2821 − 14 D2821 − 19
Standard Test Method for
Measuring the Relative Stiffness of Leather by Means of a
1
Torsional Wire Apparatus
This standard is issued under the fixed designation D2821; 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 describes the use of a torsional apparatus for measuring the relative stiffness of gloving leathers. This test
method does not apply to wet blue.
1.2 The values stated in SI units are to be regarded as the standard. The values shown in parentheses are provided for
information only.
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 safety, health, and healthenvironmental 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D1053 Test Methods for Rubber Property—Stiffening at Low Temperatures: Flexible Polymers and Coated Fabrics
D1610 Practice for Conditioning Leather and Leather Products for Testing
3. Significance and Use
3
3.1 This test method is designed to measure the apparent torsional modulus of a leather specimen. Experience has shown that
4
the torsion modulus of leather is directly related to the characteristic known as stiffness when felt in a glove.
4. Apparatus
5
4.1 Torsion Apparatus — The torsional apparatus, Fig. 1, shall consist of a torsion head, A, capable of being turned through a
complete circle in a plane normal to the torsion wire, N. The torsion head is equipped with an upper dial or protractor, K, graduated
from 0 to 360° in increments not greater than 5°, and a fixed index pointer, L. The protractor is attached to the torsion head by
1
This test method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.04 on Apparel. This test method
was developed in cooperation with the American Leather Chemists Assn.
Current edition approved April 1, 2014April 1, 2019. Published May 2014May 2019. Originally approved in 1969 as D2821 – 69T. Last previous edition approved in
20092014 as D2821 – 09.D2821 – 14. DOI: 10.1520/D2821-14.10.1520/D2821-19.
2
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.
3
This test method is similar to Test Method D1053. The original apparatus was described by Williamson, I., British Plastics, Vol 23, 1950, pp 87-90, 102; and typical
examples of the results of its use on leather were given in a paper by Witnauer, L. PA, and Palm, W.E., Journal, American Leather Chemist’s Assn., JALCA, Vol 59, 1964,
pp. 246-258.
4
Gloves were made from the neck and butt areas of cattlehide work-glove leather selected for 3° of softness varying from soft to firm. These were ranked from softest
to firmest by 20 individuals. Since there was some overlapping of rank as assigned by individual observers, the final rank was assigned according to highest number of
selections. Specimens of leather cut from the sides in the area from which each glove was cut were tested for stiffness according to this test method. At 90° of twist, the stiffness
values gave a ranking similar to that obtained by feel. Specimens cut parallel to the backbone gave more consistent ranking than specimens cut perpendicular to the backbone.
This undoubtedly reflects the fact that work gloves are cut from a side with the fingers parallel to the backbone. A report of these experiments and data used for calculation
of precision and accuracy are on file at ASTM Headquarters.
5
The sole source of supply of the apparatus known to the committee at this time is Taber Industries, 455 Bryant Street, North Tonawanda,
...