Special Rivet

Steel weld stud fully threaded

a) It is a standard that defines the specifications for cross recessed raised cheese head screws (Pan Head). These screws have a raised cylindrical head with a flat bearing surface and a cross recess, often referred to as a Phillips drive (Type H). Some other common types are cross recess type Z (Pozi) and Generic hexalobular socket / 6 lobe. 

Serrations under head / Hexalobular socket ISO 10664

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.

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.