ISO 13061-13:2024

Physical and mechanical properties of wood - Test methods for small clear wood specimens - Part 13: Determination of radial and tangential shrinkage

This document specifies a method for the determination of linear shrinkage in the radial and tangential directions of wood.

Propriétés physiques et mécaniques du bois — Méthodes d'essais sur petites éprouvettes de bois sans défauts — Partie 13: Détermination des retraits radial et tangentiel

L'ISO 13061-13 :2016 spécifie une méthode de détermination du retrait linéaire du bois dans les sens radial et tangentiel.

General Information

• Status: Published
• Publication Date: 11-Feb-2024
• ICS: 79.040 - Wood, sawlogs and sawn timber
• Technical Committee: ISO/TC 218 - Timber
• Drafting Committee: ISO/TC 218 - Timber
• Current Stage: 6060 - International Standard published
• Start Date: 12-Feb-2024
• Due Date: 23-Nov-2024
• Completion Date: 12-Feb-2024

Relations

• Revises: ISO 13061-13:2016 - Physical and mechanical properties of wood - Test methods for small clear wood specimens - Part 13: Determination of radial and tangential shrinkage
• Effective Date: 26-Nov-2022

Overview

ISO 13061-13:2024 specifies a standard test method for determining linear radial and tangential shrinkage of wood using small clear specimens. Part of the ISO 13061 series on the physical and mechanical properties of wood, this second edition updates dimensions and measurement requirements for test pieces and establishes a reproducible procedure for comparing dimensional stability across species, batches and treatments.

Key Topics and Requirements

• Scope: Measurement of linear shrinkage in the radial and tangential directions from green (or fully saturated) to oven-dry condition.
• Test pieces: Rectangular prisms cut from green wood, at least 20 mm square in the radial and tangential directions and ≥5 mm along the grain. Annual-ring inclination to tangential faces shall not exceed 10°.
• Measurement points: Marked at the centre of tangential and radial faces; dimensions measured to 0.02 mm accuracy.
• Apparatus:
  • Measuring instrument with parallel flat ends (5–8 mm diameter) and 0.02 mm precision.
  • Forced-convection oven maintained at 103 ± 2 °C.
  • Desiccator, vessel of distilled water and a balance accurate to 0.001 g.
• Procedure:
  • Ensure specimens are at or above the fibre saturation point (FSP); if below, soak in distilled water at 20 ± 2 °C and monitor until dimensional changes ≤ 0.02 mm (checks every 3 days).
  • Dry to constant mass at 103 ± 2 °C, checking mass every 8 h until mass change ≤ 0.2% or dimensional changes ≤ 0.02 mm.
  • Cool in a desiccator and re-measure radial and tangential dimensions.
• Calculation and reporting: Linear shrinkage expressed as percentage change from green to oven-dry dimensions, results rounded to 0.1%, with mean and standard deviation reported. Test report includes sampling details, measurement methods, results, date and testing organization.

Applications and Users

ISO 13061-13 is used by:

• Timber testing laboratories and wood science researchers for dimensional stability characterization.
• Quality control teams in lumber, furniture, flooring and engineered wood manufacturing to assess shrinkage-related performance.
• Engineers and designers requiring shrinkage data for structural design, joinery, drying schedules and moisture-related deformation analysis.
• Standards bodies and certification schemes that need reproducible, comparable shrinkage data across species and treatments.

Practical benefits include improved drying protocols, reduced warping/checking in production, and reliable input data for structural calculations and moisture-control strategies.

Related Standards

• ISO 3129 - Sampling and general requirements for small clear wood specimens
• ISO 24294 - Timber vocabulary
• Other parts of the ISO 13061 series covering mechanical and physical test methods for wood

Keywords: ISO 13061-13, radial shrinkage, tangential shrinkage, wood testing, physical and mechanical properties of wood, test methods for small clear wood specimens.

Standards Content (Sample)

International
Standard
ISO 13061-13
Second edition
Physical and mechanical properties
2024-02
of wood — Test methods for small
clear wood specimens —
Part 13:
Determination of radial and
tangential shrinkage
Propriétés physiques et mécaniques du bois — Méthodes d'essais
sur petites éprouvettes de bois sans défauts —
Partie 13: Détermination des retraits radial et tangentiel
Reference number
© ISO 2024
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Published in Switzerland
ii
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 Test pieces for determining radial and tangential shrinkage .2
6.3 Inclination of annual rings of test pieces .2
6.4 Marking of measurement points .2
7 Procedure . 3
7.1 Determination of the dimensions of test pieces in green or fully saturated condition .3
7.2 Determination of the dimensions of test pieces at oven-dry state .3
8 Calculation and expression of results . 3
9 Test report . 3

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 218, Timber.
This second edition of cancels and replaces the first edition (ISO 13061-13:2016), which has been technically
revised.
The main changes are as follows:
— changes in the sizes and measurements of test pieces.
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 thes
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