The bolts are part threaded and conform to DIN 931 standards. The hexagonal head has been designed for use with spanners or sockets and offers maximum torque when used with these tools.
A high tensile steel hexagon headed bolt (part-threaded)
Hexagon drive
Grade 8.8 steel
Conforms to DIN 931
Bright Zinc Plate (BZP) finish offers resistance to corrosion.