Hex screw with dog point

a) A stainless steel self-tapping thread for thermoplastics is a type of screw designed specifically to create its own threads when driven into plastic materials.

b) These screws have wider, sharp, and deep threads, which allow them to cut into the softer thermoplastic material efficiently, creating a secure, long-lasting hold.

Screw refer to ISO 14581

a) A ribbed neck screw is a type of fastener designed with a special feature on its shank or neck. Instead of a smooth or threaded surface, the neck of the screw has ribbed, serrated, or knurled features. These ribs or serrations provide additional grip and resistance when the screw is driven into a material, preventing it from rotating or loosening.

a) A self-drilling screw is a type of screw designed to drill its own hole and tap its own threads into materials as it is driven in, eliminating the need for a pre-drilled hole. The screw features a drill-like tip, often referred to a self-drilling tip, which helps the screw cut through the material. This makes installation faster and more efficient. 

b) Serrations under head create additional friction between screw head and the material. The serrated surface provides better grip for tools like screwdrivers, allowing more torque to be applied during installation.