The specification covers the requirements for locked-in studs. The method of locking in the stud is by means of a serrated collar and an accessory lockring with matching serrations installed within the parent material to prevent rotation.
This procurement specification covers inserts made from A286 alloy of the type identified under the Unified Numbering System as UNS S66286 which have non-locking internal threads and integrated locking keys to positively secure the insert against rotation when properly installed in threaded holes.
Areas for the standard metric series of thread diameter-pitch combinations for aerospace externally threaded fasteners are established for the following conditions: a) Area for ultimate shear stress or load in unthreaded shank. b) Area for ultimate tensile stress or load in thread. c) Area for stress durability test load in thread. d) Area for stress-rupture test load at elevated temperature. e) Area for tension-tension fatigue test load.