This European standard specifies the characteristics of hexagonal slotted/castellated nuts@ normal height@ normal across flats@ in heat resisting steel@ silver plated@ for aerospace applications. Classification: 1 100 MPa1/650 ??. 1 Corresponds to strength class of the associated bolt@ the 100 per cent load of which it is able to withstand@ when tested at ambient temperature@ without breaking or cracking. 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 material.