ČSN EN 4297

This European Standard specifies the characteristics of hexagonal nuts, self-locking by plastic ring, normal height, normal across flats, in corrosion resisting steel, passivated. Classification: 900 MPa 1) / 120 °C 2). 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 plastic ring.