The European standard "EN 1383 Timber structures - Test methods - Tensile strength of timber fasteners" describes a test method for determining the resistance of timber to head pullout in timber fasteners. In this standard, the term "wood" encompasses solid timber, glued laminated timber, and wood-based products. The test method described is valid for all types of nails, screws, and staples, except for fully threaded shank screws.
The moisture content and density of the timber or wood-based products tested must be determined in accordance with the relevant standards.
Test pieces should be manufactured from lumber or wood-based products at a temperature of 20°C plus or minus 2°C and an equilibrium moisture content corresponding to 65 percent plus or minus 5 percent relative humidity. The material is conditioned when it reaches constant mass. Constant mass is considered to have been reached when the material mass varies by no more than 0,1 percent after two consecutive weighings performed at 6-hour intervals.
For some investigations, different humidity conditions may be appropriate and should be reported.
The fastener's axis should be perpendicular to the surface. Fastener placement should follow standard preparation (e.g., predrilling) and application methods. Test piece dimensions should be as shown in the table provided in the standard. If test pieces are made of solid wood, half of the fasteners should be placed radially to the growth rings and half tangentially to the growth rings.
In sustainable construction, timber remains a fundamental material valued for its renewable energy, lightness, and aesthetic appeal. However, the true strength of any timber structure lies not only in the wood itself but also in the fasteners that connect it: nails, screws, and staples, which must withstand tension, shear, and environmental stresses flawlessly. EN 1383 provides a standardized method for assessing how well a fastener head resists pulling out of the timber surface under load. This standard ensures that connections in timber buildings, bridges, and furniture can withstand real-world forces, preventing premature failure that could compromise safety. As the construction industry shifts to solid timber systems like cross-laminated timber for mid- and high-rise buildings, standards like EN 1383 have become indispensable. These standards bridge the gap between material innovation and regulatory compliance.
The EN 1383 standard focuses on the susceptibility of wood fasteners to tensile failure. This failure occurs when a nail, screw, or staple head is embedded too deeply into the wood, losing its compressive strength and causing the joint to separate. This type of failure is particularly relevant in tension-loaded connections such as roof trusses, wall panels, or seismic bracing systems. This standard applies to a wide range of wood types, including solid sawn timber, glued-laminated timber (glulam), and engineered wood products such as oriented strand board or plywood.
The main objectives of this standard are:
By excluding fully threaded screws (which are covered by other standards such as EN 14592 for dowel-type fasteners), EN 1383 targets headed fasteners, making it a specialized but essential tool for fastener manufacturers and structural engineers.
The EN 1383 test method is a straightforward yet accurate method that emphasizes simplicity to ensure its widespread adoption. It uses a tensile loading rig to simulate direct tensile forces perpendicular to the wood grain and simulates lifting or splitting scenarios.
Lumber samples, typically rectangular blocks with a cross-section of 50 mm x 50 mm and a length of 100 mm, are subjected to 65 percent relative humidity and 20 percent equilibrium moisture content at 20°C. In edge tests, the grain orientation is parallel to the direction of loading.
A fastener (e.g., nail or screw) is driven perpendicular to the surface texture until the head is flush or slightly recessed. Multiple repetitions (at least three) are tested to account for variability. The tests utilize a universal testing machine equipped with a load cell (accuracy plus/minus 1 percent) and holders to securely hold the wood block and fastener shank.
To begin the test, a small initial load (e.g., 5 percent of the expected failure load) is applied to seat the specimen and remove any slack. The fastener is pulled at a constant displacement rate of 2–5 mm/min until failure occurs. Failure is defined as the point at which the head tensile displacement reaches 5 mm or the load drops to 80 percent of the maximum value. Load-displacement curves are monitored to determine the ultimate tensile load and corresponding displacement.
In short, the EN 1383 standard appears to be a simple tensile test on the surface, but its effect extends to every nailed connection point in the timber construction.
Our organization, with its competent and experienced team, has been understanding the needs of its customers for years, providing them with advanced testing services, and assisting them in establishing, implementing, and improving management systems. In this context, we also provide testing services in accordance with the EN 1383 Timber structures - Test methods - Tensile strength of wooden fasteners standard.
To get an appointment, to get more detailed information or to request an evaluation, you can ask us to fill in our form and reach you.
