Overview
EN ISO 12777-2:2000 - Methods of test for pallet joints - Part 2: Determination of withdrawal and head pull-through resistance of pallet nails and staples (ISO 12777-2:2000) specifies laboratory test methods to measure the axial resistance of pallet fasteners. The standard covers withdrawal resistance (load applied parallel or perpendicular to grain) and head pull‑through resistance for nails and staples used in pallet joints, including tests for wood-to-wood, wood-to-wood-based and wood-to-non‑wood materials (e.g., plastics).
Key topics and requirements
- Scope and fastener types: Applies to nails up to 7 mm diameter (plain, fluted, twisted, annular-thread, square, etc.) and to staples; may be suitable for other similar fasteners.
- Specimen preparation:
- Minimum recommended sample: 16 specimens per variable for statistical treatment.
- Timber selection and preparation per ISO 8970; moisture content and density measured per ISO 3130 / ISO 3131.
- Specimens must be allowed at least 16 hours after assembly before testing; delayed testing effects should be considered.
- Test geometries and dimensions:
- Withdrawal perpendicular to grain: nails driven to 8d–10d penetration; supports not closer than 6d (fibre direction) and 3d (perpendicular).
- Withdrawal parallel to grain: nails driven to 8d–16d penetration; support clearances ≥ 3d.
- Pull-through: specimen thickness ≥ 5d but not less than 12 mm (sheet materials use production thickness).
- Test procedure and measurement:
- Load applied at a constant rate of 25 ± 5 mm/min; record load–displacement (or load–time) curves.
- For pull-through, record nail head variables (shank diameter d, head diameter D, countersink angle φ) and report ultimate loads and characteristic curves.
- Material characterisation: For plastics include tensile properties, MFR/MVR (ISO 1133) and density (ISO 1183); for manufactured sheet materials document lay‑up, density and resin content.
- Reporting: Record bending strength (ISO 12777-1), withdrawal/pull-through rates, full test curves and all specimen/material data.
Practical applications
- Quality assessment of pallet nails and staples for strength and durability.
- Comparative testing of fastener designs and shank profiles for use in pallet manufacturing.
- Verifying suitability of fasteners for joining wood, plywood, particle board, and plastic pallet components.
- Input to design decisions for heavy-duty pallets, export pallets and unit-load systems where fastener axial performance is critical.
Who uses this standard
- Pallet and packaging manufacturers
- Fastener (nail/staple) manufacturers and R&D labs
- Independent materials and testing laboratories
- End-users specifying pallet performance (logistics, supply chain managers)
- Standards bodies and certification organizations
Related standards
Keywords: EN ISO 12777-2:2000, pallet nails, withdrawal resistance, head pull-through resistance, pallet joints, test methods, staples, axial load.