ISO 5858:1999 pdf download – Aerospace — Nuts, self-locking, with maximum operating temperature less than or equal to 425 °C — Procurement specification.
3.15 self-locking torque torque to be applied to the nut or bolt to maintain its movement of rotation in relation to the associated part, the assembly being under no axial load and the nut-locking system being completely engaged with the bolt (two pitches minimum protrusion, including the end chamfer) 3.16 seating torque tightening torque to be applied to the nut or bolt to introduce or to increase the axial load in the assembly 3.17 unseating torque untightening torque to be applied to the nut or bolt to reduce or remove the axial load in the assembly 3.18 breakaway torque torque required to start unscrewing the nut or bolt with respect to the associated part, with the nut-locking device still fully engaged on the bolt, but after the axial load in the assembly has been removed by unscrewing half a turn followed by a halt in rotational movement 3.19 wrench torque tightening and untightening torques which the driving feature of the nut has to withstand repeatedly without any permanent deformation which would prevent the appropriate wrench from being used or preclude re-use of the nut 4 Quality assurance 4.1 General 4.1.1 Manufacturer’s approval The manufacturer shall conform to the quality assurance and approval procedures defined by ISO 9002. The purpose of these procedures is to ensure that a manufacturer has a quality system and the capability for continuous production of nuts complying with the specified quality requirements. Approval of the manufacturer shall be granted by the Certification Authorities, or their appointed representative, who may be the prime contractor.
4.1.2 Qualification of nuts The purpose of qualification inspections and tests of nuts is to check that the design and manufacturing conditions for a nut allow it to satisfy the requirements of this International Standard. Qualification of the nuts shall be granted by the Certification Authorities in the purchaser’s country, or their appointed representative, who may be the prime contractor. 4.1.3 Production acceptance of nuts The purpose of production acceptance inspection and tests of a nut is to check, as simply as possible, using a method which is inexpensive but the most representative of the actual conditions of use, with the uncertainty inherent in statistical sampling, that the nuts satisfy the requirements of this International Standard. Production acceptance inspections and tests shall be carried out by the manufacturer, or under his responsibility. The manufacturer is responsible for the quality of the nuts manufactured.