Product Center · Thread Inserts

High-Strength Stainless Steel Wire Thread Inserts

High-strength stainless wire thread insert: 304 or 316 wire, cold-formed into a coil that puts a hard thread into a soft base.

Key specifications

MaterialSUS304/SUS316 Stainless Steel
Installationinstalled with a dedicated insert tap and driving tool
StandardGB/T 24425.1 (free-running wire thread insert)
Typical substratealuminium, magnesium, cast iron, engineering plastics
Key inspectionsfree diameter, post-install gauging, pull-out

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Product overviewOverview

The insert is a diamond-section stainless wire wound into a coil with an external thread on the outside and an internal thread on the inside. The insert does not make the joint stronger than the bolt; it moves the failure mode away from the base material. The stainless coil carries the shear that the aluminium thread could not, so the bolt shank or the bolt thread becomes the limiting part instead of the tapped hole.

Material: SUS304/SUS316 Stainless Steel. It is installed with the dedicated insert tap and its setting tool.

Key featuresFeatures

Moves failure from the soft base thread to the bolt, it does not raise bolt strength.
Diamond-section stainless wire, with hardness and tensile strength verified to the GB/T 24425 series.
Radial spring anchors the insert without adhesive; service range depends on material, commonly −50 °C to +300 °C.
Load distributes across coils, spreading stress over more threads.

Typical applicationsApplications

Aluminium die-cast housings
Magnesium structure thread repair
Aerospace light-alloy parts

Selection notesSelection

Choose 316 where chlorides are present; 304 is adequate indoors. Specify insert length by engaged thread rather than by habit, and confirm the STI tap is supplied with the insert.

Frequently asked questionsFAQ

Does an insert make the thread stronger than the bolt?

No. It replaces a soft base thread with a harder stainless one, so the bolt becomes the limiting component. Strength claims should be made against the bolt, not against the insert alone.

What matters during installation of the High-Strength Stainless Steel Wire Thread Inserts?

Tap the hole with the dedicated insert tap, then drive the insert with its setting tool. Moves failure from the soft base thread to the bolt, it does not raise bolt strength.

Specifications

Material	SUS304/SUS316 Stainless Steel
Standard	GB/T 24425.1 (free-running wire thread insert)
Installation	installed with a dedicated insert tap and driving tool
Typical substrate	aluminium, magnesium, cast iron, engineering plastics
Key inspections	free diameter, post-install gauging, pull-out

Manufacturing and inspection

Free diameter, coil count and free length are sampled to GB/T 24425, with material verified by spectrometry.We recommend a pilot assembly at the actual torque and mating part before locking the process parameters for volume.