ASTM D2941-21

Standard Test Method for Measuring Break Pattern of Leather (Break Scale)

SIGNIFICANCE AND USE
4.1 Break depends on the fiber structure and on the relation between the grain and other strata of the leather. A fine break, or a grain pattern which shows many fine wrinkles when it is bent to form a concave surface, as it is in the vamp of a shoe, reflects favorably upon appearance and serviceability. A coarse break, on the other hand, where a few coarse wrinkles are formed on bending the grain to form a concave surface may indicate that the grain layer is separating from the corium or main stratum as in pipey leather. Shoes made from fine-break leather are more attractive and tend to wear longer than shoes made from coarse-break leather. (See MIL-STD 663 and the ALCA Journal).4
SCOPE
1.1 This test method covers the measurement of the break pattern of shoe upper leather using an arbitrary break scale. This test method does not apply to wet blue or wet white.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
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: 30-Nov-2021
• ICS: 59.140.30 - Leather and furs
• Technical Committee: D31 - Leather
• Drafting Committee: D31.03 - Footwear

Relations

• Refers: ASTM D1517-15 - Standard Terminology Relating to Leather
• Effective Date: 01-Dec-2015
• Refers: ASTM D1610-01(2013) - Standard Practice for Conditioning Leather and Leather Products for Testing
• Effective Date: 01-May-2013
• Refers: ASTM D1517-10 - Standard Terminology Relating to Leather
• Effective Date: 01-Oct-2010
• Refers: ASTM D1610-01(2007) - Standard Practice for Conditioning Leather and Leather Products for Testing
• Effective Date: 01-Apr-2007
• Refers: ASTM D1517-06 - Standard Terminology Relating to Leather
• Effective Date: 01-Oct-2006
• Refers: ASTM D1517-04 - Standard Terminology Relating to Leather
• Effective Date: 01-Sep-2004
• Refers: ASTM D1517-04e1 - Standard Terminology Relating to Leather
• Effective Date: 01-Sep-2004
• Refers: ASTM D1517-99(2004) - Standard Terminology Relating to Leather
• Effective Date: 01-Apr-2004
• Refers: ASTM D1610-01 - Standard Practice for Conditioning Leather and Leather Products for Testing
• Effective Date: 10-May-2001
• Refers: ASTM D1610-00 - Standard Practice for Conditioning Leather and Leather Products for Testing
• Effective Date: 10-May-2001
• Refers: ASTM D1517-99 - Standard Terminology Relating to Leather
• Effective Date: 10-May-1999

Overview

ASTM D2941-21 is the internationally recognized standard test method for measuring the break pattern of leather using a break scale. Developed by ASTM International, this method applies to shoe upper leather and assesses the type and quality of wrinkles (break) formed on the grain surface when leather is bent. The formation of fine or coarse wrinkles significantly influences both the serviceability and appearance of finished leather goods, especially footwear. This standard is essential for manufacturers, quality control personnel, and procurement agencies seeking to accurately evaluate leather's performance attributes.

Key Topics

• Break Pattern Assessment: The break refers to the pattern of wrinkles that appear on the grain surface of upper leather when it is bent. This is a critical property, particularly in the vamp area of shoes, which undergo repeated flexing.
• Fine vs. Coarse Break:
  • Fine Break: Characterized by numerous small and even wrinkles, a fine break indicates a well-integrated grain and internal structure. Leather with a fine break is generally more attractive and tends to offer improved durability and lifespan.
  • Coarse Break: Fewer, larger wrinkles often signal separation of the grain layer from the underlying structure, sometimes resulting in loose or "pipey" leather-a sign of potential quality issues.
• Testing Equipment:
  • Satra Mandrel: Used to bend the leather specimen and simulate the stresses experienced during actual use.
  • Satra Visual Break Scale: An eight-level scale (1 = finest, 8 = coarsest) used to grade and compare wrinkle patterns.
• Test Procedure:
  • Samples are conditioned, bent on the mandrel, and observed through designated windows.
  • The break pattern is visually compared to the break scale and rated to the nearest half grade for precise classification.
• Scope Limitations: The method is not suitable for wet blue or wet white leather types.

Applications

• Footwear Manufacturing: The primary application is for shoe upper leathers, where break quality directly impacts visual appeal and product longevity. High-grade leather with a fine break is preferred in premium footwear.
• Quality Control and Specification: Leather suppliers, manufacturers, and procurement managers use ASTM D2941-21 to ensure consistency and adherence to product specifications, improving overall customer satisfaction.
• Material Research and Development: The standard supports leather technologists and R&D teams in evaluating processing techniques, tanning methods, and chemical treatments that improve break characteristics.
• Military and Commercial Contracts: Referenced by U.S. Department of Defense and other agencies, the method is often used to certify leather for contract compliance.

Related Standards

• ASTM D1517: Terminology Relating to Leather
• ASTM D1610: Practice for Conditioning Leather and Leather Products for Testing
• MIL-STD 663: Visual Inspection Guide for Footwear Upper Leather

Using ASTM D2941-21 to measure leather break pattern provides a reliable, repeatable approach to evaluating grain pattern quality and supports the production of attractive, durable leather goods. Its widespread use in footwear, quality assurance, and supply chain management helps ensure the highest standards in finished leather products.

Keywords: ASTM D2941, leather break scale, leather quality, footwear leather, grain pattern, break pattern testing, leather wrinkles, leather durability, leather standards.

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: D2941 − 21
Standard Test Method for
Measuring Break Pattern of Leather (Break Scale)
This standard is issued under the fixed designation D2941; 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. Terminology
3.1 Definitions:
1.1 This test method covers the measurement of the break
3.1.1 break (of leather)—the pattern of wrinkles formed on
pattern of shoe upper leather using an arbitrary break scale.
the grain surface of upper leather when it is bent grain in to
This test method does not apply to wet blue or wet white.
form a concave surface. This characteristic is observed in the
1.2 The values stated in inch-pound units are to be regarded
vamp of the shoe in walking. For this reason this test method
as standard. The values given in parentheses are mathematical
is primarily intended for evaluation of cut parts.
conversions to SI units that are provided for information only
3.2 For definitions of other terms used in this test method,
and are not considered standard.
refer to Terminology D1517.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Significance and Use
responsibility of the user of this standard to establish appro-
4.1 Break depends on the fiber structure and on the relation
priate safety, health, and environmental practices and deter-
between the grain and other strata of the leather. A fine break,
mine the applicability of regulatory limitations prior to use.
or a grain pattern which shows many fine wrinkles when it is
1.4 This international standard was developed in accor-
bent to form a concave surface, as it is in the vamp of a shoe,
dance with internationally recognized principles on standard-
reflects favorably upon appearance and serviceability.Acoarse
ization established in the Decision on Principles for the
break, on the other hand, where a few coarse wrinkles are
Development of International Standards, Guides and Recom-
formed on bending the grain to form a concave surface may
mendations issued by the World Trade Organization Technical
indicate that the grain layer is separating from the corium or
Barriers to Trade (TBT) Committee.
main stratum as in pipey leather. Shoes made from fine-break
leather are more attractive and tend to wear longer than shoes
2. Referenced Documents
made from coarse-break leather. (See MIL-STD 663 and the
2 4
2.1 ASTM Standards: ALCA Journal).
D1517 Terminology Relating to Leather
5,6
5. Apparatus
D1610 Practice for Conditioning Leather and Leather Prod-
ucts for Testing
5.1 Satra Mandrel, consisting of two windows or hollows.
2.2 MIL Standard:
5.2 Satra Visual Break Scale, consisting of eight levels of
MIL-STD 663 Visual Inspection Guide for Footwear Upper
break ranging from 1, fine, to 8, coarse.
Leather
6. Test Specimen
6.1 The sample for the test should be taken from an agreed
This test method is under the jurisdiction ofASTM Committee D31 on Leather
area of the hide, and shall be a piece of leather 2 in. by 4 in.
and is the direct responsibility of Subcommittee D31.03 on Footwear. This test
method was developed in cooperation with the American Leather Chemists Assn.
(Standard Method E64 – 1972).
Current edition approved Dec. 1, 2021. Published January 2022. Originally Bailey, M., Journal of the American Leather Chemists Association, JALCA,
approved in 1970. Last previous edition approved in 2013 as D2941 – 13. DOI: Vol 53, 1958, p. 568.
10.1520/D2941-21. Landmann, A. W., and Thompson, R. S., Journal of the Society of Leather
For referenced ASTM
...

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: D2941 − 13 D2941 − 21
Standard Test Method for
Measuring Break Pattern of Leather (Break Scale)
This standard is issued under the fixed designation D2941; 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 covers the measurement of the break pattern of shoe upper leather using an arbitrary break scale. This test
method does not apply to wet blue.blue or wet white.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
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
2.1 ASTM Standards:
D1517 Terminology Relating to Leather
D1610 Practice for Conditioning Leather and Leather Products for Testing
2.2 MIL Standard:
MIL-STD 663 Visual Inspection Guide for Footwear Upper Leather
3. Terminology
3.1 Definitions:
3.1.1 break (of leather)—the pattern of wrinkles formed on the grain surface of upper leather when it is bent grain in to form a
concave surface. This characteristic is observed in the vamp of the shoe in walking. For this reason this test method is primarily
intended for evaluation of cut parts.
3.2 For definitions of other terms used in this test method, refer to Terminology D1517.
This test method is under the jurisdiction of ASTM Committee D31 on Leather and is the direct responsibility of Subcommittee D31.03 on Footwear. This test method
was developed in cooperation with the American Leather Chemists Assn. (Standard Method E64 – 1972).
Current edition approved May 1, 2013Dec. 1, 2021. Published May 2013January 2022. Originally approved in 1970. Last previous edition approved in 20122013 as
D2941 – 00D2941 – 13.(2012). DOI: 10.1520/D2941-13.10.1520/D2941-21.
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.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2941 − 21
4. Significance and Use
4.1 Break depends on the fiber structure and on the relation between the grain and other strata of the leather. A fine break, or a
grain pattern which shows many fine wrinkles when it is bent to form a concave surface, as it is in the vamp of a shoe, reflects
favorably upon appearance and serviceability. A coarse break, on the other hand, where a few coarse wrinkles are formed on
bending the grain to form a concave surface may indicate that the grain layer is separating from the corium or main stratum as
in pipey leather. Shoes made from fine-break leather are more attractive and tend to wear longer
...