General description The Concrete Frame Screws are designed for easy installation and high durability. Made from hardened steel with a self-tapping head, these screws are perfect for fixing window and door frames to masonry or concrete walls without the need for anchors or plugs. The zinc plating offers temporary rust protection, making them suitable for generally dry environments. Technical specifications Size: 7.5mm x 52mm Recommended screw diameter: 6.5mm Material: Galvanized alloy steel Usage Ideal for fastening window and door frames to masonry or concrete walls Can also be used with roofing