Screw for thin sheet metal and wood 4.2x25mm /500pcs/ WF-4225

Universal solution for fastening thin materials

The Koelner B-WF-4225 self-tapping screw with a diameter of 4,2 mm and a length of 25 mm is a professional fastener designed for the durable fastening of thin steel sheet elements, PVC profiles, and structural wood. Thanks to its special point design, no pre-drilling of holes is required, which significantly accelerates assembly work.

Construction and materials ensuring durability

The hardened thread surface guarantees high resistance to mechanical wear during repeated driving and removal. A zinc coating with a minimum thickness of 5 microns effectively protects against corrosion even in humid working conditions, extending the service life of connections made with these screws.

The wafer head type flat head is integrated with a washer, providing greater resistance to head pull-through and an aesthetic surface finish after fastening. The flat surface of the head allows for secure pressure on the fastened element without the risk of damaging delicate materials.

Application in diverse projects

The product is effective for the installation of roofing sheets, wall panels, finishing strips, and wood-metal structures. It is ideally suited for fastening thin metal sheets and thin wood panels.

Correct installation guaranteeing safety

The screw should be installed perpendicular to the substrate (90° angle) using a screwdriver with adjustable torque or a depth limiter. When starting installation, work at low speeds (1600-2000 rpm), reducing the speed in the final phase of driving for precise seating.

Avoid using high-power drills that may damage the thread or cause cracking of the material being fastened. Before starting work, ensure that the thickness of the substrate material meets the minimum requirements specified by the manufacturer.

Compliance with European standards

The product meets the requirements of the PN-EN 14566 + A1:2012 standard regarding self-drilling screws for wood and holds the Declaration of Performance DoP-EN14566-WFS confirming its performance parameters and safety of use.

An A1 class fire reaction means the material is fully non-combustible, allowing for safe use in buildings with increased fire safety requirements and industrial installations where contact with an open flame is possible.

The package contains 50 pieces of screws placed in a practical blister pack that facilitates storage and transport to the construction site or assembly workshop.