ISO 13061-5:2020

Physical and mechanical properties of wood - Test methods for small clear wood specimens - Part 5: Determination of strength in compression perpendicular to grain

This document specifies a method for determining the strength in compression perpendicular to grain of wood.

Propriétés physiques et mécaniques du bois — Méthodes d'essais sur petites éprouvettes de bois sans défauts — Partie 5: Détermination de la résistance en compression perpendiculaire au fil

General Information

• Status: Published
• Publication Date: 05-Jan-2020
• ICS: 79.040 - Wood, sawlogs and sawn timber
• Technical Committee: ISO/TC 218 - Timber
• Drafting Committee: ISO/TC 218/WG 4 - Test methods
• Current Stage: 9093 - International Standard confirmed
• Start Date: 18-Jun-2025
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 3132:1975 - Wood - Testing in compression perpendicular to grain
• Effective Date: 12-Aug-2017

Overview

ISO 13061-5:2020 is an international standard that specifies a precise test method for determining the strength of wood under compression perpendicular to the grain. This standard is part of the ISO 13061 series, focusing on the physical and mechanical properties of wood through tests on small clear specimens. It provides a reliable procedure applicable to various wood species, enabling consistent assessment of mechanical strength when subjected to loads across the grain direction.

Developed by ISO Technical Committee ISO/TC 218 (Timber), the standard replaces the previous ISO 3132:1975 and introduces technical revisions such as updated specimen dimensions and moisture content adjustments. It ensures conformity and comparability of results essential for material selection, quality control, and research in wood engineering and construction industries.

Key Topics

• Scope and Purpose: Defines the determination method of compressive strength perpendicular to grain using small, defect-free wood specimens.
• Test Specimen Preparation: Instructions on specimen dimensions, moisture content conditions (green or air-dry), and conditioning to ensure accurate and reproducible results.
• Testing Apparatus:
  • A testing machine capable of controlled loading
  • Uniform-loading devices with self-aligning hardened steel plates
  • Precision displacement and dimension measuring instruments
• Test Procedure:
  • Application of a gradually increasing load to the entire surface of the specimen in radial, tangential, or 45° orientation relative to growth rings
  • Measurement of load and deformation to determine the proportional limit from the load-deformation curve
• Calculations:
  • Stress at the proportional limit computed by dividing the corresponding load by the specimen’s bearing area
  • Adjustment of results to a standard 12% moisture content when required, using recognized correction factors
• Reporting Requirements:
  • Details of sampling, specimen dimensions, moisture content, density, loading direction, test speed, and statistical values of results
  • Compliance reference to ISO 13061-5:2020 for traceability and standardization

Applications

ISO 13061-5:2020 is vital for evaluating wood material performance in various fields, including:

• Wood Engineering and Construction: Ensures the safe and reliable design of wooden structures by providing accurate compressive strength data perpendicular to grain, which affects connections, supports, and load-bearing components.
• Material Quality Control: Enables manufacturers and suppliers to verify wood strength properties to meet required standards and optimize product use.
• Research and Development: Serves as a reference for studying wood mechanical behavior, quality assessment, treatment effects, and species comparison.
• Timber Industry Certification: Assists certification bodies in validating timber properties against recognized international standards to support trade and compliance.
• Product Testing Laboratories: Provides standardized methods for consistent measurements, fostering international comparability of test results.

Related Standards

• ISO 13061-1: Determination of moisture content - addresses moisture measurement essential for conditioning specimens in mechanical tests.
• ISO 13061-2: Determination of density - specifies how to measure wood density as part of the characterization process for mechanical testing.
• ISO 3129: Sampling methods and general requirements for physical and mechanical tests - guides specimen sampling and handling to meet test integrity requirements.
• ISO 24294: Timber vocabulary - supplies consistent terminology related to wood and timber properties referenced across ISO 13061 standards.

---

Adherence to ISO 13061-5:2020 ensures precise evaluation of wood’s compressive strength perpendicular to grain, critical for multiple industrial sectors relying on wood as a structural material. The standard formulates a uniform testing approach that supports sustainable and safe utilization of wood resources worldwide.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 13061-5
First edition
2020-01
Physical and mechanical properties of
wood — Test methods for small clear
wood specimens —
Part 5:
Determination of strength in
compression perpendicular to grain
Propriétés physiques et mécaniques du bois — Méthodes d'essais sur
petites éprouvettes de bois sans défauts —
Partie 5: Détermination de la résistance en compression
perpendiculaire au fil
Reference number
©
ISO 2020
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 1
6 Preparation of test pieces . 2
6.1 General . 2
6.2 Dimensions of test pieces . 2
6.3 Moisture content of test pieces . 2
7 Procedure. 2
8 Calculation and expression of results . 3
9 Test report . 5
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 218, Timber.
This first edition of ISO 13061-5 cancels and replaces ISO 3132:1975, which has been technically revised.
The main changes are as follows:
— sizes, moisture content of test pieces and adjustment for moisture content have been technically
revised;
— some sentences were reconstructed for clarity.
A list of all parts in the ISO 13061 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2020 – All rights reserved

Introduction
The main purpose of this document is to establish the common standard concerning testing methods
for small clear wood specimens and general requirements for determining physical and mechanical
properties of wood.
INTERNATIONAL STANDARD ISO 13061-5:2020(E)
Physical and mechanical properties of wood — Test
methods for small clear wood specimens —
Part 5:
Determination of strength in compression perpendicular
to grain
1 Scope
This document specifies a method for determining the strength in compression perpendicular to grain
of wood.
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 3129, Wood — Sampling methods and general requirements for physical and mechanical tests
ISO 13061-1, Physical and mechanical properties of wood — Test methods for small clear wood specimens —
Part 1: Determination of moisture content for
...