Type

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.

Application

Primarily to provide hard, wear-resistant internal screw threads in light alloys or nonmetals, to provide the parent tapped material increased shear strength by installing an insert of sufficient length to develop the full load of the bolt, and for salvaging worn or damaged internal threads.