DIN251 Hexagon Socket Head Serrated Flange Screws

DIN 251 Hexagon Socket Head Serrated Flange Screws combine a cylindrical socket head with an integrated serrated flange designed to improve resistance to loosening. The toothed flange increases the grip between the screw and the mating surface, while the internal hexagon drive allows installation in applications where access for conventional external wrenches is limited.

The integrated flange also provides a larger bearing surface than a standard socket head screw, helping distribute the clamping load over the joint surface. DIN 251 screws can be supplied in carbon and alloy steel as well as stainless steel, with suitable property classes and surface finishes for different mechanical and environmental requirements. These screws are suitable for machinery, equipment, brackets, fabricated components, automotive assemblies, and other bolted connections where compact installation and improved resistance to loosening are required. Available dimensions include metric sizes from M3 to M30, depending on the required specification.

Specification:

DIN 251 Hexagon Socket Head Serrated Flange Screws are manufactured with an integrated serrated flange and internal hexagon drive for compact and secure bolted connections. The serrated flange provides an increased bearing surface and helps resist relative movement at the joint, while the socket drive allows installation where access for external tools is limited. Carbon steel and alloy steel versions can be supplied in property classes 8.8, 10.9 and 12.9, with mechanical properties according to ISO 898-1. Stainless steel versions are available in A2 and A4 grades, with the applicable stainless steel fastener requirements. Metric threads are supplied according to the relevant ISO metric thread system, with dimensions and tolerances controlled according to the applicable product requirements.

Dimension Chart of DIN251 Hexagon Socket Head Serrated Flange Screws：

Selecting a DIN 251 screw requires more than matching the nominal thread size. The thread pitch, overall length, head dimensions, flange diameter, and hexagon socket size all affect how the screw fits and performs in an assembly. Use the dimension chart to compare the available sizes and select the configuration that matches your component and installation space. The detailed dimensions and tolerances for each size are listed in the chart below. All dimensions are given in millimeters unless otherwise specified.