This International Standard specifies the dimensions of self-locking, fixed, closed corner anchor nuts, reduced series, with counterbore, with MJ threads, of classifications: 1 100 MPa 1) /235 °C 2) , 1 100 MPa 1) /315 °C 2) and 1 100 MPa 1) /425 °C 2). This International Standard is only applicable for the compilation of aerospace product standards. 1) 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. 2) 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.