Concealed screw installation with Stålviks’ Concealed Deck Tool—a truly sturdy, professional-grade tool for those who want the very best. Absolutely not to be confused with simple plastic tools. Of course, at wholesale prices. Stålviks—for concealed screw installation of decking. Using Stålviks’ tool, the screw is installed into the side of the decking board, resulting in a concealed installation. An extremely powerful and stable tool for maximum performance; its center of gravity ensures stability during installation. Stålviks tools are designed for 22–34 mm decking and are adjustable for deck board widths between 95–150 mm.Stålviks comes with three different spacers, allowing for a choice of spacing at either 3.5, 4.5, or 5.5 mm. The Stålvik tool is used in conjunction with a special screw and is installed using a custom bit included with the tool. It is located in the tool’s handle. Torx 15 bit with a stop edge, ensuring the screw is driven to the exact depth in the wood. The tool can also be used with screws from other manufacturers, such as Essve, Camo, Fast, Heco, Mft, Vsb, Gunnebo, and others. Stålviks Deck Screw A4, Class C5, marine-grade, acid-resistant, concealed deck screw. 4.8 x 60 is used for boards with a thickness of 22–35 mm (e.g., 22, 28, 32, 34 mm). Special screw designed for use with the installation tool. Equipped with a self-tapping tip and a reverse thread under the head that presses the decking board against the underlying joist. A T15 100 mm bit is included in the package and is attached to the tool’s handle. Material: Acid-resistant A4 stainless steel. NOTE! We recommend only acid-resistant A4 (not C4 or A2 stainless steel)