General description The Timco Wing Tip heavy section screw is specifically designed for attaching wood to heavy section steel, with a maximum thickness of 12mm. It features a fine self-tapping thread with wings that ream out the timber, allowing the screw to achieve maximum RPM without burning out. When the wings contact the metal, they break off to enable the thread to self-tap into the metal. Technical specifications Size: 5.5 x 85mm Box Quantity: 100 Colour/Plating: Zinc Head Type: Phillips Countersunk Bit Size: PH3 Other information Bright zinc electrolytic plating with a clear toxin-free finish.