SIST EN ISO 3378:2003

Leather - Physical and mechanical tests - Determination of resistance to grain cracking and grain crack index (ISO 3378:2002)

ISO 3378:2002 specifies a method for determining the resistance of leather to grain cracking and for determining the grain crack index. It is applicable to all heavy leathers.

Leder - Physikalische und mechanische Prüfungen - Bestimmung des Widerstandes gegen Narbenplatzen und des Narbenbruchindex (ISO 3378:2002)

Diese Internationale Norm legt ein Verfahren zur Bestimmung des Widerstandes von Leder gegen Narbenplatzen sowie zur Bestimmung des Narbenbruchindexes fest. Es ist für alle schweren Leder anwendbar.

Cuir - Essais physiques et mécaniques - Détermination de la résistance a la gerçure de la fleur et indice de gerçure (ISO 3378:2002)

L'ISO 3378:2002 spécifie une méthode de détermination de la résistance du cuir à la gerçure de la fleur et de détermination de l'indice de gerçure. Elle est applicable à tous les cuirs épais.

Usnje - Fizikalni in mehanski preskusi - Ugotavljanje odpornosti lica proti razpokanju in indeksa razpokanja (ISO 3378:2002)

General Information

• Status: Published
• Publication Date: 31-Jan-2003
• ICS: 59.140.30 - Leather and furs
• Technical Committee: IUSN - Leather
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Feb-2003
• Due Date: 01-Feb-2003
• Completion Date: 01-Feb-2003
• Ref Project: EN ISO 3378:2002 - Leather - Physical and mechanical tests - Determination of resistance to grain cracking and grain crack index (ISO 3378:2002)

Overview

SIST EN ISO 3378:2003 is an international standard developed by CEN and ISO, detailing the physical and mechanical testing methods for leather, specifically focusing on the determination of resistance to grain cracking and the grain crack index. This standard applies to all heavy leathers and provides a consistent framework for evaluating leather durability regarding grain surface integrity under stress. The method prescribed helps manufacturers, quality control labs, and researchers assess leather performance to ensure longevity and suitability for various applications.

Key Topics

• Scope and Applicability
  SIST EN ISO 3378:2003 covers testing procedures to determine how resistant leather is to cracking on its grain surface. It is applicable to heavy leather types used in diverse industries.

• Test Principle
  Leather samples are bent grain outwards around cylindrical mandrels of various diameters. The test checks for cracking, quantifying resistance by the size of mandrels causing grain cracks.

• Apparatus and Sampling
  The apparatus involves a test machine with clamps, rollers, and mandrels ranging from 6.76 mm to 61.67 mm in diameter. Test pieces are cut from leather samples precisely following ISO 2418 and conditioned per ISO 2419 for consistent testing environments.

• Testing Procedure
  Leather pieces are bent 180° around each mandrel while under controlled force. Observers note any grain cracking to evaluate cracking resistance.

• Grain Crack Index Calculation
  The grain crack index is determined by multiplying the diameter number of the largest mandrel causing grain crack by the leather thickness. This value provides a numerical index of leather's grain cracking performance.

• Test Reporting
  Reports include references to the standard, mandrel sizes used, pass/fail results, grain crack index values, conditioning atmosphere, and any deviations from the prescribed method.

Applications

• Leather Manufacturing Quality Assurance
  This standard ensures that heavy leather products meet specified durability requirements, reducing recalls and increasing customer satisfaction.

• Footwear and Leather Goods Industry
  Products like shoes, bags, and belts rely on this testing to guarantee the leather withstands bending stresses without grain cracks, ensuring product longevity.

• Automotive and Upholstery Leather Testing
  Heavy leather used in car seats and furniture benefits from grain crack resistance testing to maintain aesthetic and functional integrity over time.

• Research and Development
  Leather technologists and chemists use SIST EN ISO 3378:2003 to study new tanning processes or additives that improve grain crack resistance.

• Regulatory Compliance
  Meeting this standard helps companies comply with industry and regional regulations regarding product quality and safety.

Related Standards

• ISO 2418:2002 – Leather sampling location for chemical, physical, mechanical, and fastness tests ensuring representative test pieces.
• ISO 2419:2002 – Methods for sample preparation and conditioning vital for reproducible testing results.
• ISO 2589:2002 – Procedures for determining leather thickness, key for calculating the grain crack index accurately.

Summary

SIST EN ISO 3378:2003 provides a practical, repeatable method for assessing leather’s resistance to physical grain cracking. Employing controlled bending around mandrels, it quantifies leather durability critical for manufacturers and quality assessors targeting high-performance heavy leather products. Compliance assures enhanced quality control, product reliability, and supports continued innovation in leather processing technologies. This standard is a fundamental reference in the leather physical testing domain, promoting worldwide consistency and material excellence.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2003
Usnje - Fizikalni in mehanski preskusi - Ugotavljanje odpornosti lica proti
razpokanju in indeksa razpokanja (ISO 3378:2002)
Leather - Physical and mechanical tests - Determination of resistance to grain cracking
and grain crack index (ISO 3378:2002)
Leder - Physikalische und mechanische Prüfungen - Bestimmung des Widerstandes
gegen Narbenplatzen und des Narbenbruchindex (ISO 3378:2002)
Cuir - Essais physiques et mécaniques - Détermination de la résistance a la gerçure de
la fleur et indice de gerçure (ISO 3378:2002)
Ta slovenski standard je istoveten z: EN ISO 3378:2002
ICS:
59.140.30 Usnje in krzno Leather and furs
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 3378
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2002
ICS 59.140.30
English version
Leather - Physical and mechanical tests - Determination of
resistance to grain cracking and grain crack index (ISO
3378:2002)
Cuir - Essais physiques et mécaniques - Détermination de Leder - Physikalische und mechanische Prüfungen -
la résistance à la gerçure de la fleur et indice de gerçure Bestimmung des Widerstandes gegen Narbenplatzen und
(ISO 3378:2002) des Narbenbruchindex (ISO 3378:2002)
This European Standard was approved by CEN on 9 September 2002.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3378:2002 E
worldwide for CEN national Members.

CORRECTED  2003-08-27
Foreword
This document (EN ISO 3378:2002) has been prepared by Technical Committee CEN/TC 289
"Leather", the secretariat of which is held by UNI, in collaboration with the International Union of
Leather Technologists and Chemists Societies (IULTCS).
It is based on Method IUP 12 of the International Union of Leather Technologists and Chemists
Societies.
This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by June 2003, and conflicting national
standards shall be withdrawn at the latest by June 2003.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 3378:2002 has been approved by CEN as EN ISO 3378:2002 without any
modifications.
NOTE Normative references to International Standards are listed in Annex ZA (normative).
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated
by (mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 2418 2002 Leather - Chemical, physical EN ISO 2418 2002
and mechanical and fastness
tests - Sampling location
ISO 2419 2002 Leather - Physical and EN ISO 2419 2002
mechanical tests - Sample
preparation and conditioning
ISO 2589 2002 Leather - Physical and EN ISO 2589 2002
mechanical tests -
Determination of thickness
INTERNATIONAL ISO
STANDARD 3378
IULTCS/IUP
Second edition
2002-12-15
Leather — Physical and mechanical
tests — Determination of resistance to
grain cracking and grain crack index
Cuir — Essais physiques et mécaniques — Détermination de la résistance
à la gerçure de la fleur et indice de gerçure

Reference number
ISO 3378:2002(E)
IULTCS/IUP 12
©
ISO 2002
ISO 3378:2002(E)
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ISO 3378:2002(E)
Contents
Page
Foreword . iv

1 Scope .1
2 Normative references .1
3 Principle.1
4 Apparatus .1
5 Sampling and sample preparation .3
6 Procedure .3
7 Expression of results .3
8 Test report .4
Annex A (informative) The derivation of a grain crack index .5
Annex B (informative) Sources of apparatus .6
ISO 3378:2002(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards adopted
by the technical committees are circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies cas
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