ISO 9609:1996, Aerospace - Nuts, hexagonal, plain, reduced height, normal across flats, with MJ threads, classifications: 450 MPa (at ambient ... C, 600 MPa (at ambient temperature) /4

Specifies the dimensions of plain, hexagonal nuts, reduced height, normal across flats, with MJ threads. The given classification corresponds to the minimum tensile stress which the nut is able to withstand at ambient temperature without breaking or cracking.