Flanged base eliminates the need for a washer when fastening components
Self-locking serrated flange digs into the material being fastened to help prevent loosening
Hex body has six flat sides that a wrench can grip to turn from the side, enabling use when there is no space above the nut
Grade 2 steel is often used in applications where toughness is the primary consideration, while the zinc plating resists corrosion and has a reflective appearance