The SPAX typical drive T-STAR plus is a so-called internal hexagon. This shape increases the contact area 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, significantly more efficiently than with any other drive. The countersunk head (or flat countersunk head) mills 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 along 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 S-tip is characterized by the fact that the thread extends into the front flanks. When you position the screw and start the cordless screwdriver, this thread immediately grips in the wood and pulls the screw in effortlessly. This allows for fast work without the workpiece being scratched by the slipping screw tips. The abbreviation A2 in our stainless steel screws comes from the alloy of the steel. Screws made of stainless steel A2 offer high protection against corrosion and medium strengths. Their resistance to seawater and acids is low. Therefore, they are used for outdoor applications in areas away from the coast.