ASTM D2821-00

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

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 problems, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Sep-2000
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.04 - Apparel

Relations

• Replaced By: ASTM D2821-00(2005) - Standard Test Method for Measuring the Relative Stiffness of Leather by Means of a Torsional Wire Apparatus
• Effective Date: 01-Sep-2005

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D2821–00
Standard Test Method for
Measuring the Relative Stiffness of Leather by Means of a
Torsional Wire Apparatus
This standard is issued under the fixed designation D 2821; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Apparatus
1.1 This test method describes the use of a torsional 4.1 Torsion Apparatus —The torsional apparatus, Fig. 1,
apparatus for measuring the relative stiffness of gloving leath- shall consist of a torsion head, A, capable of being turned
ers. This test method does not apply to wet blue. through a complete circle in a plane normal to the torsion wire.
1.2 The values stated in SI units are to be regarded as the The torsion head is equipped with an upper dial or protractor,
standard. The values shown in parentheses are provided for K, graduated from 0 to 360° in increments not greater than 5°,
information only. and a fixed index pointer, L. The protractor is attached to the
1.3 This standard does not purport to address all of the torsion head by means of a friction bearing to permit move-
safety concerns, if any, associated with its use. It is the ment for adjusting the zero point. The top of the torsion wire is
responsibility of the user of this standard to establish appro- attached to the torsion head at knob H by set screw B and
priate safety and health practices and determine the applica- passes through the center of a loosely fitting sleeve gripped by
bility of regulatory limitations prior to use. the friction bearing. The torsion head support carries a split
bearing which can be activated by knob G, thus locking the
2. Referenced Documents
sleeve carrying the wire and permitting adjustment of the zero
2.1 ASTM Standards:
point of the protractor without disturbing the position of the
D 1053 Test Method for Rubber Property-Stiffening at Low torsionwire.Thebottomofthewireshallbefastenedtothetest
Temperatures: Flexible Polymers and Coated Fabrics
specimen clamp, C, by means of a set screw connector, D.A
D 1610 Practice for Conditioning Leather and Leather pointer, I, mounted above a fixed dial, J, shall be provided to
Products for Testing
indicatethetwistappliedtothespecimen.Torsionisappliedby
manually turning knob H or the remote control knob M.
3. Significance and Use
4.2 Stand—The torsion apparatus shall be mounted on a
3.1 This test method is designed to measure the apparent
rigid supporting stand.
torsionalmodulusofaleatherspecimen.Experiencehasshown
4.3 Torsion Wires —Torsion wires shall be made of tem-
that the torsion modulus of leather is directly related to the
pered spring wire 315 mm (12.5 in.) long, with each end firmly
characteristic known as stiffness when felt in a glove.
affixed within a rod measuring 5 mm ( ⁄16 in.) in diameter and
The method is similar to Test Method D 1053. The original apparatus was
This test method is under the jurisdiction ofASTM Committee D31 on Leather described by Williamson, I., British Plastics, Vol 23, 1950, pp. 87–90, 102; and
and is the direct responsibility of Subcommittee D31.04 onApparel and Upholstery. 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.,
This test method was developed in cooperation with theAmerican Leather Chemists
JALCA, Vol 59, 1964, pp. 246–258. Working drawings for construction of the
Assn.
Current edition approved Sept. 10, 2000. Published October 2000. Originally apparatus are available at nominal cost fromASTM Headquarters, 100 Barr Harbor
{1
published as D 2821 – 69T. Last previous edition D 2821 – 79 (1998) . Drive, W. Conshohocken, PA19428-2959. RequestAdjunctADJD282102. There is
Annual Book of ASTM Standards, Vol 09.01. no known source of supply of the equipment. The former producer, Fulton County
Annual Book of ASTM Standards, Vol 15.04. Machine and Supply Co., Inc. is no longer in business. If you are aware of
Gloves were made from the neck and butt areas of cattlehide work-glove alternative suppliers, please provide this information to ASTM Headquarters. Your
leather selected for 3° of softness varying from soft to firm.These were ranked from comments will receive careful consideration at a meeting of the responsible
softest to firmest by 20 individuals. Since there was some overlapping of rank as technical committee, which you may attend.
assigned by individual observers, the final rank was assigned according to highest Lengths of the standard wire can be obtained at nominal cost fromASTM, 100
numberofselections.Specimensofleathercutfromthesidesintheareafromwhich Barr Harbor Drive, W. Conshohocken, PA 19428-2959. Request Adjunct
each glove was cut were tested for stiffness according to this test method.At 90° of ADJD282101.Astainlesssteelrocketwire,TypeNS-302,0.010 60.0025in.(0.025
twist, the stiffness values gave a ranking similar to that obtained by feel. Specimens 6 0.06 mm) in diameter, bright finish, with chemical composition of 0.08 to 0.12 %
cut parallel to the backbone gave more consistant ranking than specimens cut carbon, 8 to 10 % nickel, and 17 to 19 % chromium, available from National
perpendicular to the backbone. This undoubtedly reflects the fact that work gloves Standard Co., 1618-T Terminal Road, Niles, MI 49120; telephone: [phone];
are cut from a side with the fingers parallel to the backbone. A report of these fax: [phone]; has proved satisfactory. If other wire is used, it should be
experiments and data used for calculation of precision and accuracy are on file at calibrated as described in Test Method D 1053 and have a constant of 0.0182
ASTM Headquarters. g·cm/deg.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2821
6.5 Unlock the top dial by turning knobG counterclockwise
about ⁄4turn.
6.6 Bring both clamps into parallel position by turning knob
H, or knob M, either clockwise or counterclockwise so there is
no twist to the specimen. When the clamps are parallel adjust
the top clamp indicator, I, so it is over the “0” mark on the
lower dial, J, by holding the clamp parallel in one hand and
turning the indicator. The indicator is attached to the upper
clamp by a friction clasp.
6.7 Lock the top dial, K, by turning knob G clockwise until
tight.
6.8 Set the top dial by actually turning dial K to read 270°
(top dial is tension fitted).
NOTE 1—By setting the dial to 270°, the 90° twist of the specimen will
be subtracted out automatically, and the readings obtained will be that of
the wire to give the desired 90° twist of the specimen.
NOTE 2—When setting top dial care should be taken not to twist the
wire, causing the top clamp indicator to move. Movement of the indicator
means
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