Product and application brief
A moulded-in thread insert is positioned in the mould before the surrounding plastic component is formed. Its internal thread provides the screw interface; its outside features and mould location define the interface with the host. This is a different manufacturing route from fitting a heat, ultrasonic, press-in or self-tapping insert into an already moulded part. Select the insert together with the mould and finished-component drawing.
Product forms and reference names
| Choice or field | What to identify |
|---|---|
| Through-hole body | SPIROL Series63 is an original through-hole moulded-in example with a symmetric body. This orientation feature belongs to that selected construction, not to all inserts with two open ends. |
| Blind-ended body | SPIROL Series65 uses a related body with one closed end. Identify the internal usable thread and screw-end clearance separately from total insert length. A blind thread in the finished plastic part does not by itself prove that the metal insert is closed. |
| Coiled mould-in bushing | Böllhoff IMTEC CO uses specially rolled wire formed into a bushing with a flange-like extension and is primarily identified for components with blind-hole threads. It is positioned during moulding, not installed into a tapped metal hole as a thread-repair coil. |
| Double-flanged formed insert | Böllhoff IMTEC CF is a cold-formed, double-flanged construction primarily for through-hole applications. Its designed deformation region relates to mould closing and length adjustment. Do not treat a rigid generic sleeve or ordinary nut as having the same mould interface. |
Core-pin fit is not the mating screw specification
Record the selected core-pin reference, location datum and insert-to-pin interface separately from the final screw thread. Ask the mould designer to confirm placement, retention, alignment and closure clearance. The original maker examples use controlled locating interfaces; an M-size alone does not define a pin diameter or mould tolerance. No magnetic handling or automated feeding compatibility is established for an unspecified insert.
Specify polymer and surrounding geometry
Provide the exact resin, thermoplastic or thermoset identity, filler type/content and relevant moulding condition. Identify boss walls, surrounding features and available polymer around the retention profile. Do not transfer the material suitability or test data of one original maker series to a different alloy, shape, resin or component.
Protect the thread during forming
Define how the selected insert and mould prevent unwanted plastic entry into the threaded bore. Show the open or closed end, core-pin contact, required thread access and finished thread inspection. A closed end is a construction choice, not a general leak-tightness or sealing claim. Handling cleanliness and the completed part need their own acceptance requirements.
Outside retention and installed position
Identify flanges, grooves, knurls or other defined outside features from the exact drawing, without inferring a retention rating from appearance. Specify exposed or embedded faces, axial location, orientation and the installed thread datum. A formed insert with a selected deformation zone requires its own before/after geometry and mould-closing specification; no generic compression allowance is given here.
Thread insert versus compression limiter
An internally threaded insert and a compression limiter serve different interfaces. If one selected construction is also required to carry a stand-off or compression-limiting role, show that function, mating faces and load path in the assembly drawing. Do not infer it from a flange or substitute a plain sleeve for a threaded insert. Drawing-defined spacer and limiter enquiries remain separate.
Accept the finished component, not the picture
Define insert supply inspection and finished moulded-assembly acceptance separately: thread access/inspection, installed position, host condition and project-specific qualification. Manufacturer guide test examples are not ratings for your component. No pull-out, torque-out, temperature, reuse, sealing or tightening value is prescribed. Actual resin, geometry and forming process require the selected verification plan.
Specification fields
| Choice or field | What to identify |
|---|---|
| Reference and route | Exact product/series code or drawing/revision; placed before moulding rather than post-mould installation; relevant open/closed-end and flanged/coiled/formed variant. |
| Thread and length | Internal thread system, size, pitch and fit; total body length versus usable thread, screw engagement and closed-end clearance. |
| Outside geometry | Retention profile, flange/waist/groove details; orientation and permitted deformation only where specified for the selected product. |
| Resin and host | Exact resin and filler; component/boss drawing, surrounding walls and intended service exposure. |
| Mould interface | Core-pin and tooling reference, placement/retention, location datum, thread protection and closure/part-release requirements confirmed by mould designer. |
| Finished acceptance | Installed datum and accessible thread; insert/host inspection and any assembly qualification/test records required by the project. |
| Material and order | Insert alloy/condition/finish independent of resin; quantity by exact variant, packaging/documents and requested date; actual supply scope confirmed per order. |
Common product questions
Is a moulded-in insert interchangeable with a heat-set insert?
No interchangeability is established. One is located before the plastic part is formed; the other is fitted afterward. Select each host and installation interface separately.
Does a blind-hole thread always require a closed metal end?
Not from the name alone. Distinguish the metal insert end construction from the finished host cavity and specify thread protection, screw clearance and any actual sealing requirement.
Can the reference image determine the mould or core-pin dimensions?
No. It shows generic appearance only, without tolerances, a deformation-zone definition or a tool interface. Use the selected controlled drawings.
Related product choices
- After-moulding inserts: separate installation mechanisms
- Wire inserts for prepared metal threads: separate host interface
- Drawing-defined spacers and compression-limiter requirements
- 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.