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 screwdriver to the screw through T-STAR plus enables fast work, significantly more efficient than with any other drives. The countersunk head (also known as 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 is 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 S-tip is characterized by the fact that the thread is formed all the way to the front flanks. When you place the screw and start the cordless screwdriver, this thread immediately grips the wood and effortlessly pulls the screw in. This allows for quick work without the workpiece being scratched by the slipping screw tips. The abbreviation A2 for 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 in outdoor applications in areas far from the coast.