Spectre(tm) by Forgefix, incorporates a long list of advanced screw features, often only found in premium screws, into what we've named advanced multi-purpose wood screws. They feature a countersunk, pozidrive compatible, recessed head. Fully threaded, up to 50mm, with a sawtooth thread, to prevent splitting, and reamer to prevent jacking (50mm and above). They are also surface hardened with a quick start type 17 slash point. Specification: Size: 4.0 x 40mm. Thread: Fully threaded. Pack Quantity: Tub of 1,200. Spectre(tm) by Forgefix, incorporates a long list of advanced screw features, often only found in premium screws, into what we've named advanced multi-purpose wood screws. They feature a countersunk, pozidrive compatible, recessed head. Fully threaded, up to 50mm, with a sawtooth thread, to prevent splitting, and reamer to prevent jacking (50mm and above). They are also surface hardened with a quick start type 17 slash point. The screws have a zinc yellow passivated finish for excellent resistance to corrosion. Zinc yellow passivation process of electroplating is similar to the 'galvanised' and 'zinc plated' processes, but with the addition of a yellow dye. It offers an aesthetically pleasing finish. CE approved for use in load-bearing timber construction. ForgeFix A04 B2050