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 transfer from the driver to the screw through T-STAR plus enables quick work, and it is significantly more efficient than all other drives. The countersunk head (or flat countersunk head) carves a recess into the wood with its polygonal underside ("pockets") and can therefore 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 screw's core diameter. This reduces the spreading pressure that the core exerts on the wood and prevents splitting near the edges. The required torque of the cordless screwdriver is also reduced, as the core of the screw does not have to be "squeezed" into the wood. With WIROX, SPAX has developed a coating that far surpasses 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 non-directly weathered outdoor areas. 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 variants.