ISO 18333:2014

Pallets for materials handling - Quality of new wooden components for flat pallets

ISO 18333:2014 gives guidance on minimum recommended timber quality characteristics. It is applicable to new stringers, stringerboards, blocks, and deckboards used for flat wooden pallet assembly. ISO 18333:2014 does not address the phytosanitation and safety problems, if any, associated with the use of these components.

Palettes pour la manutention et le transport de marchandises — Qualité des composants neufs en bois pour palettes plates

General Information

• Status: Published
• Publication Date: 24-Jun-2014
• ICS: 55.180.20 - General purpose pallets
• Technical Committee: ISO/TC 51 - Pallets for unit load method of materials handling
• Drafting Committee: ISO/TC 51 - Pallets for unit load method of materials handling
• Current Stage: 9093 - International Standard confirmed
• Start Date: 09-May-2025
• Completion Date: 13-Dec-2025

Relations

• Revises: ISO 18333:2002 - Pallets for materials handling - Quality of new wooden components for flat pallets
• Effective Date: 28-Jan-2012

Overview

ISO 18333:2014 - "Pallets for materials handling - Quality of new wooden components for flat pallets" specifies minimum recommended timber quality characteristics for new wooden pallet components. It applies to stringers, stringerboards, blocks, and deckboards used in flat wooden pallet assembly. The standard sets quality levels, manufacturing tolerances and preparation rules that influence pallet strength, fit and functionality. It does not cover phytosanitation or safety issues related to wood (see ISPM 15 and national regulations).

Key topics and technical requirements

• Quality levels (Q1 / Q2): Components shall meet minimum limits for knots, splits, shakes, resin pockets, bark pockets, wane, blue stain and insect damage as summarized in Table 1 of the standard. Stringerboards are recommended to be Q1.
• Knots and defects: Limits on sound/intergrown knots, loose or unsound knots, exposed pith, boxed heart, face shake and splits; special restrictions apply in the notch area of stringers.
• Moisture content: No fixed moisture-content limit, but below 20% moisture content is associated with minimal biological infestation risk. Dimensional change guidance: assume ±0.25% dimension change per 1% moisture change relative to 20% (increase from 20–30% or decrease below 20%).
• Manufacturing tolerances:
  • Deckboards and stringerboards: thickness ±1.5 mm, width ±3 mm, length ±3 mm.
  • Stringers and blocks: width ±1.5 mm, height ±1.5 mm, length ±3 mm.
• Deckboard chamfer: If specified, chamfers on bottom end boards and interior edges should be 65 mm from stringers/blocks at an angle of 40° ± 5°, with vertical face ≤16 mm.
• Stringer notches: Notch depth + bottom deck thickness ≥ 50 mm; recommended 180 mm minimum flat top; fillet radius 13–37 mm; dimensional tolerances ±3 mm (notch location ±6 mm). Restrictions on knots and wane in the notch area to protect structural integrity.

Applications and users

ISO 18333:2014 is intended for:

• Pallet manufacturers and assemblers specifying component quality for reliable pallet performance.
• Timber and component suppliers setting procurement quality criteria.
• Quality engineers and inspectors verifying conformity of wooden pallet parts.
• Logistics, packaging and materials-handling professionals concerned with unit-load efficiency and pallet fit in handling systems. Using ISO 18333 helps reduce failures from poor timber quality, improve interchangeability, and support consistent pallet performance across supply chains.

Related standards

• ISO 15629 - Quality of fasteners for pallet assembly
• ISO 18334 - Quality of assembly of new wooden pallets
• ISO 18613 - Repair of flat wooden pallets
• ISO 6780 - Flat pallet dimensions and tolerances
• ISPM 15 - Phytosanitary regulation for wood packaging

Keywords: ISO 18333:2014, pallet components, wooden pallets, stringers, deckboards, quality, manufacturing tolerances, moisture content, pallet standards.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 18333
Second edition
2014-07-01
Pallets for materials handling —
Quality of new wooden components
for flat pallets
Palettes pour la manutention et le transport de marchandises —
Qualité des composants neufs en bois pour palettes plates
Reference number
©
ISO 2014
© ISO 2014
All rights reserved. Unless otherwise specified, 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
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Published in Switzerland
ii © ISO 2014 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Species . 3
5 Quality characteristics. 3
6 Moisture content of components . 3
7 Preparation of pallet components . 3
7.1 Manufacturing tolerances . 3
7.2 Deckboard chamfer . 5
7.3 Stringer notches . 5
Bibliography . 7
Foreword
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bodies (ISO member bodies). The work of preparing International Standards is normally carried out
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committee has been established has the right to be represented on that committee. International
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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
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assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 51, Pallets for unit load method of materials
handling.
This second edition cancels and replaces the first edition (ISO 18333:2002), which has been technically
revised.
iv © ISO 2014 – All rights reserved

Introduction
Efficient international transportation of products depends on both pallet strength and functionality,
or fit, to the material handling systems. Existing International Standards address issues of strength
and some issues regarding functionality of pallets. However, major issues related to the minimum
material quality and manufacturing and repair workmanship are not addressed in current International
Standards. These factors can significantly impact the efficiency of international unit load material
handling practices.
The purpose of this International Standard is to establish internationally recognized minimum
acceptable quality levels for wooden parts commonly used for the assembly of timber pallets. These
parts are stringers, stringerboards, blocks, and deckboards. The properties of these components affect
pallet performance.
There are four related International Standards:
— ISO 15629;
— ISO 18333;
— ISO 18334;
— ISO 18613.
INTERNATIONAL STANDARD ISO 18333:2014(E)
Pallets for materials handling — Quality of new wooden
components for flat pallets
1 Scope
This International Standard gives guidance on minimum recommended timber quality characteristics.
It is applicable to new stringers, stringerboards, blocks, and deckboards used for flat wooden pallet
assembly.
This International Standard does not address the phytosanitation and safety problems, if any, associated
with the use of these components.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 445, Pallets for materials handling — Vocabulary
EN 844-3, Round and sawn timber — Terminology — Part 3: General terms relating to sawn timber
EN 844-9, Round and sawn timber — Terminology — Part 9: Terms relating to features of sawn timber
EN 844-10, Round and sawn timber — Terminology — Part 10: Terms relating to stain and fungal attack
EN 844-12, Round and sawn timber — Terminology — Part 12: Additional terms and general index
International Standards for Phytosanitary Measures Publication No. 15 (ISPM 15), Regulation for wood
packaging material in international trade
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 445, EN 844-3, EN 844-9,
EN 844-10 and EN 844-12 and the following apply.
3.1
bark pocket
bark that is partly or wholly enclosed in the wood
3.2
boxed heart
pith that is present and not visible in any face or edge
3.3
decay
disintegration of the wood substance due to actions of wood-destroying fungi
3.4
exposed pith
pith that is visible on a part or the full length of a face or on an edge
3.5
face shake
fissure showing on a face and possibly at the end
3.6
fungal decay
biodeterioration caused by fungi
3.7
heart shake
radial end shake originating at the pith
3.8
intergrown knot
knot that, on the surface considered, is intergrown with the surrounding wood for more than three
quarters of its cross-sectional perimeter
3.9
oblique shake
fissure at an angle to the arris, showing on a face and/or an edge
3.10
resin p
...