Hexagon socket screws

From plan view, the head of the hexagon socket screw shows a regular hexagon, limited by six rectangles of the same size on the sizes. The hexagon socket screw is the cheapest and most wide-spread screw type, manufactured in the largest quantity. It is used in situations where it is possible to reach the screw head with a wrench from the outside. For hexagon socket screws, we normally use spanners, ring spanners and socket wrenches.

Screws categorized by material or material quality
  • iron
  • toughened steel
  • anti-corrosion steel (A2)
  • acid-resistant steel (A4)
  • yellow copper
  • aluminium
  • chemically resistant plastic (PA)
The most common types in function of quality
  • 5.6 hexagon socket screw
  • 8.8 hexagon socket screw
  • 10.9 hexagon socket screw
Types
  • DIN 933 – full-thread hexagon socket screw 
  • DIN 931 – partial-thread hexagon socket screw
  • DIN 960 – partial, fine-thread hexagon socket screw 
  • DIN 961 – full, fine-thread hexagon socket screw
  • DIN 6921 – flange hexagon socket screw (knurled or smooth)

The DIN 6921 flange hexagon socket screw are most commonly used in the machine industry, for example, car manufacturing, lifts. The flange gives greater fastening torque and the knurled design further increases the tightness of the binding.

Flange hexagon socket screws are available in almost all kinds of variation, e.g. wooden screw, board screw, self-drilling screw, metric thread screws or threads by inch.