Astm D 4831 – 00 pdf free download

Standard Test Method for
Buckle Tear Strength of Leather1

This standard is issued under the fixed designation D 4831; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of the 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

1.1 This test method is intended for use on all types of
leather to determine the load required to tear a leather strap
fastened in a buckle. This test method does not apply to wet
blue.

1.2 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 and health practices and determine the applicability of regulatory limitations prior to use.

2. Significance and Use

2.1 This test method is designed to measure the load
required to tear a leather strap fastened in a buckle. Tanners and
leather buyers have found that this test gives an indication of
the resistance of leather to tearing.

2.2 This test method should be suitable for specification
acceptance, design purposes, manufacturing control, development, and research. The thickness of the specimen and the direction of the tear relative to the backbone will affect the uniformity
of the test results. This test method may not apply when the
conditions of the test employed differ widely from those
specified in this test method.

3. Apparatus

3.1 Gage, spring-type, for measuring the thickness of units,
graduated in 0.5 oz or 0.1 mm having a flat pressure foot of 0.4 6
0.025 in. (10.2 6 0.6 mm) in diameter and a flat anvil of 0.4 6
0.025 in. in diameter. The spring shall exert a force of 1 lb
(4.45 N) on the foot when the gauge reads 2 oz and 2 lb (8.9 N)
when the gage reads 12 oz.

3.2 Steel Punch, which will make a 3⁄16 in. (4.8 mm)
diameter hole.

3.3 Harness Buckle, 1.25 in. (4.7 mm) with a 0.175 6
0.005-in. (4.4 6 0.1-mm) diameter tongue. It shall be attached
to a strong strap, 1.25 in. wide and at least 5 in. (127 mm) long.
The strap shall be equipped with a keeper located approximately 0.75 in. (19 mm) from the buckle.

3.4 Testing Machine, power-driven. The applied load shall
be indicated on a dial, scale, or chart. The load indicator shall
record or indicate the maximum load at the time of rupture o