Weld Stud

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. 

a) DIN 933 refers to a standard for hexagon head bolts with full threads. These bolts are commonly used in mechanical and structural applications that require high strength and reliable fastening.

b) Typically made from carbon steel, stainless steel, or alloy steel. They are available with various surface finishes, such as zinc plating, hot-dip galvanizing, or black oxide, to improve corrosion resistance and enhance durability.

a) A self-tapping screw for thermoplastics is a specialized fastener designed to create its own threads as it is 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.

Flat head weld stud with metric thread

Square neck under head