ISO 9609:2016 specifies the dimensions of plain, hexagonal nuts, reduced height, normal across flats, with MJ threads, of classifications: 450 MPa/120 °C, 450 MPa/235 °C, 600 MPa/425 °C, 900 MPa/235 °C, 900 MPa/315 °C, 900 MPa/650 °C, 1 100 MPa/235 °C, 1 100 MPa/730 °C, and 1 250 MPa/600 °C.

NOTE 1 450 MPa, 600 MPa, 900 MPa, 1 100 MPa and 1 250 MPa corresponds to the minimum tensile stress which the nut is able to withstand at ambient temperature without breaking or cracking when tested with a bolt of a higher strength class.

NOTE 2 120 °C, 235 °C, 425 °C, 315 °C, 650 °C, 730 °C and 600 °C corresponds to the maximum temperature that the nut is able to withstand without permanent alteration to its original characteristics, after ambient temperature has been restored. The maximum temperature is conditioned by the surface treatment.

Nuts provided with holes are intended to be used with lockwire in conformity with ISO 245.

ISO 9609:2016 is only applicable for the compilation of aerospace product standards.