ISO 20940:2021

INTERNATIONAL ISO
STANDARD 20940
First edition
2021-04
Leather — Crust full chrome upper
leather — Specifications and test
methods
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Characteristics . 3
4.1 Physical characteristics . 3
4.2 Chemical characteristics . 6
5 Sampling . 6
6 Packaging and marking . 6
6.1 Packaging . 6
6.2 Marking . 6
Bibliography . 7
Foreword
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This document was prepared by Technical Committee ISO/TC 120, Leather, Subcommittee SC 2, Tanned
leather.
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iv © ISO 2021 – All rights reserved

Introduction
Leather is widely used in the footwear industry. Although different tanning agents can be used to
make leather, chromium III is still the most important agent in the tanning of leather for footwear. This
document specifies requirements for various types of crust full chrome upper leather which are used in
the footwear industry for making upper leather.
INTERNATIONAL STANDARD ISO 20940:2021(E)
Leather — Crust full chrome upper leather —
Specifications and test methods
1 Scope
This document specifies requirements, methods of testing and methods of sampling for crust full
chrome upper leather to be used in all types of footwear (see Table 1).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 2418, Leather — Chemical, physical and mechanical and fastness tests — Sampling location
ISO 2588, Leather — Sampling — Number of items for a gross sample
ISO 3376, Leather — Physical and mechanical tests — Determination of tensile strength and percentage
elongation
ISO 3377-2, Leather — Physical and mechanical tests — Determination of tear load — Part 2: Double
edge tear
ISO 3379, Leather — Determination of distension and strength of surface (Ball burst method)
ISO 4045, Leather — Chemical tests — Determination of pH and difference figure
ISO 4048, Leather — Chemical tests — Determination of matter soluble in dichloromethane and free fatty
acid content
ISO 5398-1, Leather — Chemical determination of chromic oxide content — Part 1: Quantification by
titration
ISO 5402-1, Leather — Determination of flex resistance — Part 1: Flexometer method
ISO 11640, Leather — Tests for colour fastness — C
...