Hexagon socket countersunk head screws
Due to their head geometry, countersunk-head screws have a limited load capacity according to this standard and may not meet the requirements for the tensile or torsional strength. The actual mechanical properties of the screw are unchanged and comply with ISO 3506-1.
Depending on the type, these items are supplied with threading almost up to the head.
Countersinks for screw heads in accordance with DIN 7991 and ISO 10642 must comply with DIN 74 shape F
DIN 7991 has been withdrawn and replaced by ISO 10642. There is some limited similarity (some head heights and head diameters have been changed | nominal Ø M18, M22, M24 are omitted | Stainless steels removed | strength classes 10.9 and 12.9 added). Due to their head geometry, these screws can only be subjected to limited loads, see DIN EN ISO 3506-1