Product and application brief
A wire thread insert is a continuous formed-wire coil that provides the internal screw thread when fitted into a prepared receiving thread. It is not a solid threaded sleeve, compression spring or loose washer. Start with the mating thread and selected insert design, then define the receiving interface in the host component. This page helps organise a drawing-based enquiry; it does not approve a repaired or loaded connection.
Product forms and reference names
| Choice or field | What to identify |
|---|---|
| Tanged construction | An installation tang is a driving feature on selected designs. State the chosen product instructions and whether removal and recovery are required; tang handling is not a locking classification. |
| Tang-free construction | A selected tang-free design uses its own driving interface and matched installation equipment. No automatic compatibility with tools for a tanged insert is implied. |
| Free-running thread | Identify the non-locking thread version explicitly. This choice is independent of whether the insert has a tang. |
| Screw-locking thread | A selected locking version has a designed clamping region, such as polygonal turns in manufacturer examples. State the exact product and mating screw requirements; colour or tang status does not prove locking performance. |
| ISO metric reference | DIN 8140-1:2022-04 identifies wire inserts for ISO metric screw threads. It is not a general equivalence claim for imperial threads or every proprietary insert series. |
Separate tang handling from locking
Treat installation-interface selection and screw-running behaviour as two fields. Manufacturer families include free-running and locking versions in tang-free constructions. Some maker-specific retained-tang systems also exist; do not extend their handling rules to all inserts. A generic image cannot show or certify a screw-locking characteristic.
Receiving thread is a separate interface
DIN 8140-2:2005-08 identifies receiving coil threads and their tolerances; DIN 8140-3:2017-05 identifies gauges. Their catalogue records are current at review; the separately listed 2025-11 Part 3 draft is not treated as a released replacement. The nominal mating screw thread alone does not supply drill size, receiving tap, gauge or installation depth. Use the selected insert/system drawing for those values, with host wall thickness and blind-hole clearance checked independently.
Installed length and host geometry
Identify installed insert length and its datum separately from the free coil appearance or turn count. Supply the internal thread designation, host alloy, hole condition, receiving-thread drawing, available depth, entry condition and end clearance. A blind hole and a through hole require their own selected arrangement; no universal depth or wall allowance is supplied here.
Keep material and approval questions open
Record insert material and any coating separately from the host alloy. Existing or damaged receiving threads need a selected repair assessment, not an assumption that an insert restores every original strength requirement. Required gauging, inspection and qualification records must be defined for the actual application. No retention load, prevailing torque, temperature, corrosion, repeated-use or tool-compatibility guarantee is made.
Specification fields
| Choice or field | What to identify |
|---|---|
| Insert identity | Exact standard and edition, maker series or controlled drawing/revision; tang/tang-free and free-running/locking selections. |
| Mating thread | Internal screw thread system, nominal diameter, pitch and required fit; mating screw material/grade and any selected locking restrictions. |
| Insert geometry | Installed length and datum, free-state dimensions only where specified, insertion depth and end clearance from the chosen drawing. |
| Host and receiving thread | Host alloy/condition, receiving-thread specification and tolerance, hole type, wall/edge clearance, repair condition and controlled hole drawing. |
| Installation and inspection | Selected tap, gauge and installation-tool references, approved tang handling/recovery method, inspection criteria and access; not generic settings. |
| Material and finish | Insert material/coating and host surface condition; application-specific temperature/corrosion or qualification requirements supplied separately. |
| Order and documents | Quantity by size/variant, units, bulk or supplied presentation, required reports and packing/destination/date; availability and delivery require confirmation. |
Common product questions
Does tang-free mean screw-locking?
No. Tang handling describes the installation interface; free-running or locking describes the selected thread behaviour. Specify both independently.
Can I prepare the hole using only the screw size?
No. The insert receiving thread, tap and gauge follow the selected system and drawing; the mating screw designation is only one input.
Is a coil image proof of a conforming repair insert?
No. It is only appearance reference. Dimensions, material, qualification and application acceptance require separate controlled evidence.
Related product choices
- Solid-body metal inserts: separate construction
- Thread inserts and clinch fasteners
- Thread specification checklist
Product references
References checked 10 October 2026 identify structures, not FastenerBridge stock, certification or brand affiliation. Final requirements follow the selected specification. No universal dimensions, load rating or tightening torque is stated.