Description
Click here to download the MBS Countersunk Screw Technical Data Sheet
MBS self-tapping frame screws are specifically engineered for the direct fixing of window frames, door frames, and subframes into solid and semi-solid building materials, including natural stone, solid and hollow concrete, lightweight and aerated concrete, solid brick, and hollow brick.
Featuring a specialised HI-LOW thread design, these screws provide a secure fixing even when installed close to the edge of the substrate. The reduced installation stress helps minimise the risk of material damage while ensuring excellent holding strength. The through-fixing installation method also promotes even load distribution across the supporting structure for enhanced long-term performance.
Manufactured from high-quality electro-galvanised carbon steel, MBS frame screws offer excellent durability and corrosion resistance for internal and protected external applications. The unique HI-LOW thread geometry reduces contact pressure within the substrate, allowing reliable anchorage without compromising the integrity of the surrounding material.
The performance of MBS frame screws has been independently tested by the renowned IFT Rosenheim Institute for Window and Façade Technology, one of Europe's leading certification bodies for window and frame components. The countersunk head design allows the screw to sit neatly within PVC frames without damaging the profile, providing a clean finish and dependable performance under real-world service conditions.
Suitable for use in both solid and semi-solid substrates, MBS self-tapping frame screws are designed for Service Classes SC1 and SC2. Their self-tapping design enables direct installation into masonry with minimal preparation, significantly reducing installation time while helping to improve accuracy on site. The result is a fast, secure, and dependable fixing solution for professional frame installation.
MBS vs MBZ Frame Screws
Choosing between MBS and MBZ frame screws depends primarily on the frame material and the required head style.
MBS screws feature a countersunk head, making them the ideal choice for PVC and aluminium frames. The low-profile head sits flush with the frame, preventing damage to the frame profile while providing a neat, professional finish.
MBZ screws are manufactured with a cylindrical head, specifically designed for timber frames. The head penetrates and remains recessed within the timber, delivering a discreet finish and excellent holding performance in solid wood applications.
Which should you choose?
- PVC or aluminium frames: Choose MBS with its countersunk head for a flush, damage-free installation.
- Solid timber frames: Choose MBZ with its cylindrical head for secure anchorage and a recessed finish.
Both screw types provide fast, reliable fixing into solid and semi-solid masonry substrates, but selecting the correct head design ensures optimum performance for your specific frame material.
