The cross recess Z is a further development of the cross drive by the Phillips Screw Company. The difference is that the four flanks of the screwdriver blade do not taper towards the tip. This increases the lateral hold for the screwdriver bit and reduces the cam-out effect. Typical tapering on conventional cross recess drives causes this to happen, since the cordless screwdriver torque pushes the screwdriver bit upwards.
The countersunk head (also known as the flat countersunk head) has a polygonal underside ("pockets") that mills its way into the wood and can therefore be countersunk without having to pre-drill the screw hole. The flat countersunk head sits flush with the surface.
Unlike the partial thread, the full thread spans the entire screw length. The more thread turn a screw has, the greater the tensile and compressive forces that can be transferred by these screws to the wood. Our full-thread screws are predominantly used for heavy-duty wood connections.
The term 4CUT stands for the arrow-shaped design of the screw tip. These edges displace the wood fibres upon insertion and create space for the core diameter of the screw. The expansion at the core of the wood is reduced, preventing wood splitting around the edges. The required cordless screwdriver torque is also reduced, since the screw core no longer needs to "squeeze" into the wood.
With WIROX, SPAX has developed a coating that is far superior to galvanisation when it comes to corrosion protection. No chromium(VI) is used for WIROX, which means that even after years in an area not directly exposed to the elements, the screws are not only just as resilient, but are entirely environmentally friendly, too. WIROX screws are the ideal choice for all open structures without direct exposure to the elements, such as carports and pergolas. For areas with direct weather exposure, such as decking, we recommend our stainless-steel screws.
