ISO 13061-3-2014 PDF

Full title and description

Physical and mechanical properties of wood — Test methods for small clear wood specimens — Part 3: Determination of ultimate strength in static bending. ISO 13061‑3:2014 specifies a laboratory method for determining the ultimate bending strength (breaking stress) of small, clear (defect‑free) wood specimens using a simply supported, mid‑span loaded beam (three‑point bending) arrangement.

Abstract

ISO 13061‑3:2014 defines specimen requirements, apparatus, test setup and procedure, and calculation and expression of results for static three‑point bending tests on small clear wood specimens. The standard provides a repeatable procedure to measure breaking load and to calculate bending strength (modulus of rupture) for research, material characterization and quality control of timber and wood products. The part is intended to be used alongside other parts of the ISO 13061 series (for moisture conditioning, density, modulus of elasticity, etc.).

General information

• Status: Published (International Standard).
• Publication date: 15 December 2014 (Edition 1:2014); amended in 2017 (Amendment 1).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 79.040 — Wood, sawlogs and sawn timber.
• Edition / version: Edition 1 (2014); ISO 13061‑3:2014/Amd 1:2017 (amendment).
• Number of pages: 5 (core document).

Scope

This part of ISO 13061 specifies a method to determine the ultimate strength in static bending of small clear wood specimens using a simply supported beam loaded at mid‑span (three‑point bending). It covers specimen selection and preparation, test machine and support geometry, loading rate, data to be recorded, calculation of bending stress (modulus of rupture) and reporting requirements. The method is intended for use with prismatic specimens free from visible defects and for material characterization, comparison of materials, and laboratory quality control. It does not cover full‑scale structural members or long‑term/fatigue bending behaviour.

Key topics and requirements

• Specimen selection and preparation: small, clear, defect‑free prismatic specimens with specified orientation (grain direction) and dimensional tolerances.
• Test fixture and geometry: simply supported beam with specified span‑to‑depth ratio and mid‑span loading (three‑point bending).
• Loading procedure: controlled displacement or load rate to produce static failure at a measurable breaking load; recommended speeds and preconditioning of specimens.
• Measurements and data recording: breaking load (Fmax), specimen dimensions (span, width, thickness), and environmental/moisture conditions at test time.
• Calculations: expression of bending strength (modulus of rupture, MOR) from breaking load and specimen geometry (standard rectangular beam bending formula), with instructions for rounding and reporting units.
• Conditioning and moisture: requirement to report specimen moisture content and reference to ISO 13061‑1 for moisture determination and to the series guidance for converting results to a reference moisture content (commonly 12 %).
• Reporting: test method identification, specimen details (species, orientation, density, moisture), test machine details, support and loading geometry, test speed, raw results and calculated MOR values, and any deviations from the standard procedure.
• Safety and apparatus calibration: guidance to ensure load frame, supports and loading noses are appropriate and calibrated for valid results.

Typical use and users

ISO 13061‑3:2014 is used by materials testing laboratories, university and research groups studying wood mechanics, timber and engineered wood product manufacturers for product development and quality control, certification and grading bodies, and engineers needing consistent small‑specimen bending data for material selection and comparative studies.

Related standards

Key related documents include other parts of the ISO 13061 series: ISO 13061‑1 (moisture content for tests), ISO 13061‑2 (density), ISO 13061‑4 (modulus of elasticity in bending), ISO 13061‑12 (static hardness), and other parts addressing additional properties and test methods. ISO 13061‑3:2014 replaces the earlier ISO 3133:1975 (withdrawn). An amendment (ISO 13061‑3:2014/Amd 1:2017) was published to update/correct the original text; some national bodies have produced related adoptions or revisions in subsequent years.

Keywords

wood testing, bending strength, static bending, modulus of rupture, MOR, small clear specimens, three‑point bending, ISO 13061, timber testing, specimen conditioning, moisture content

FAQ

Q: What is this standard?

A: ISO 13061‑3:2014 is the ISO test method for determining the ultimate (breaking) strength of wood in static bending using small clear specimens in a three‑point bending configuration.

Q: What does it cover?

A: It covers specimen preparation, test setup (simply supported beam with mid‑span loading), test procedure, data to record, calculation of bending strength (modulus of rupture) and reporting requirements for small, defect‑free wood specimens.

Q: Who typically uses it?

A: Test laboratories, researchers, timber and engineered wood manufacturers, certification and grading organizations, and engineers who need standardized small‑specimen bending data.

Q: Is it current or superseded?

A: ISO 13061‑3:2014 was published on 15 December 2014 (Edition 1) and published an amendment in 2017 (Amendment 1). It replaced ISO 3133:1975. National adoptions and subsequent national amendments/revisions (e.g., certain 2023 national publications) exist—users should verify the latest local adoption or revision with their national standards body if they require the absolute latest version.

Q: Is it part of a series?

A: Yes — it is Part 3 of the ISO 13061 series, a suite of test methods for physical and mechanical properties of wood on small clear specimens (other parts cover moisture content, density, modulus of elasticity, hardness, swelling and related test methods).

Q: What are the key keywords?

A: Bending strength, static bending, modulus of rupture (MOR), three‑point bending, small clear specimens, wood testing, ISO 13061, timber testing, specimen conditioning, moisture content.