This specification covers closely-wound helical coil, screw thread inserts made of a corrosion resistant steel formed wire with a chemical composition in accordance with Table 1 and identified under the Unified Numbering System as UNS S30200 or UNS S30400 that can be formed by an insert manufacturer to achieve the requirements of this procurement specification. The inner surface of the insert coil, after assembly into a screw thread tapped hole, provides internal threads of standard 60° Unified form.