The SPAX typical drive T-STAR plus is a so-called internal hexagon. This shape increases the contact surface of our T-STAR plus, allowing the T-STAR plus bits to fit optimally in the screw head. The best possible power transmission from the screwdriver to the screw through T-STAR plus enables quick work and is significantly more efficient than with any other drives. The countersunk head (or flat countersunk head) cuts a recess into the wood with its polygonal underside ("pockets"), allowing it to be sunk without additional countersinking of the screw hole. The countersunk head sits flush with the surface. Unlike partial threads, the full thread extends over the entire length of the screw. The more thread turns a screw has, the greater the tensile and compressive forces that can be transferred from the screw to the wood. Our full-thread screws are primarily used for highly stressed wood connections. The term 4CUT refers to the square shape of the screw tip. These edges displace the wood fibers during insertion and create space for the core diameter of the screw. The spreading pressure exerted by the core in the wood is thus reduced, preventing the wood from splitting near the edge. The necessary torque of the cordless screwdriver is also reduced, as the core of the screw does not have to "squeeze" into the wood. With WIROX, SPAX has developed a coating that is far superior to galvanization in terms of corrosion protection. WIROX does not use chromium (VI), and the screws remain just as load-bearing and environmentally friendly even after years in outdoor areas not directly exposed to the weather. WIROX screws are the first choice for all open structures without direct weather exposure, such as carports or pergolas. For direct weather exposure, such as on terraces, we recommend our screws in stainless steel.