This standard specifies product grade A hexagon socket thin head cap screws with pilot recess for wrench key with ISO metric screw thread from M4 up to and including M36.

If, in special cases, the screws are to meet requirements other than those given in this standard, e.g.with regard to property class or material, these shall be selected in accordance with the appropriate standard. This also applies to the fine pitch thread conforming to DIN 13 Part 13 required in exceptional cases.

The critical cross section of screws covered by this standard can as a consequence of the head geometry and the form of the wrench engagement, be located below the hexagon socket and not in the thread. This particularly applies for fine pitch thread screws and/or where tolerance positions are unfavourable (see also Explanatory notes}. It is thus recommended that the screws should not be used for the transmission of high axial loads involving prestressing.

These screws can not be used in the form of screw assemblies with captive washers as specified in DIN 6900, as they are always required to have a short unthreaded portion of shank to compensate for the pilot recess, taking into account strength criteria.