Buy Threaded Inserts Online in Australia
AIMS Industrial stocks Recoil 304 stainless steel wire thread inserts — the workshop-standard method for repairing stripped threads and creating durable threads in soft or repeatedly-assembled materials such as aluminium, cast iron and timber. Our range covers metric inserts from M3 to M24, UNC inserts from #10-24 to 7/8-9, and UNF inserts from #10-32 to 3/4-16, plus a Recoil Keysert key-locking insert and a dedicated M14 x 1.25 spark plug thread repair kit. Every insert we stock is genuine Recoil, manufactured to NASM8846 dimensional tolerances, so it installs with standard STI taps and matches the sizes engineers and mechanics already know. We've put together a Stripped Thread Repair Guide: Helicoil, Recoil & Inserts if you'd like more detail before you buy.
Whether you're repairing a stripped sump plug thread, reinforcing a soft alloy casting, or fixing a worn spark plug hole in a cylinder head, our team can help you match the insert, tap and installation tool to the job. Call us on (02) 9773 0122 or see the range below.
Quick Reference — Recoil Inserts AIMS Stocks
| Type | Thread Range | Material | Best For |
|---|---|---|---|
| Wire Thread Insert — Metric | M3-0.5 to M24-3 (1D/1.5D/2D lengths) | 304 Stainless Steel | General thread repair & reinforcement in aluminium, cast iron, timber |
| Wire Thread Insert — UNC | #10-24 to 7/8-9 (1.5D length) | 304 Stainless Steel | Imperial coarse-thread repair — US-spec machinery, older equipment |
| Wire Thread Insert — UNF | #10-32 to 3/4-16 (1.5D length) | 304 Stainless Steel | Imperial fine-thread repair — automotive & precision assemblies |
| Wire Thread Insert — Left Hand | 9/16-20 UNF x 1/2" | 304 Stainless Steel | Left-hand thread applications (specialised — confirm before ordering) |
| Keysert (key-locking) | M10-1.5 x 14mm | 304 Stainless Steel | Higher pull-out resistance, anti-rotation in soft/heavily loaded hosts |
| Spark Plug Thread Repair | M14-1.25 x 3/4" | 304 Stainless Steel | Stripped spark plug threads in aluminium cylinder heads |
Wire Thread Inserts — the Recoil Range
Wire thread inserts are precision-coiled, diamond-section stainless steel wire that spring into a tapped oversize hole to create a new internal thread. Once installed, they distribute clamping load across the full length of the insert rather than a single tapped thread, which is why a correctly installed insert in aluminium routinely outlasts the original alloy thread. Our free-running tanged inserts (e.g. the M12-1.75 x 2D 10-pack) require the installation tang to be snapped off flush after fitting — standard practice for this insert style.
We stock the Recoil metric range from M3 through to M24, in 1D, 1.5D and 2D lengths (the "D" denotes multiples of the nominal thread diameter — longer inserts suit softer host materials, shorter lengths suit harder or thinner sections). Imperial coverage runs UNC #10-24 to 7/8-9 and UNF #10-32 to 3/4-16, both at 1.5D length, so most Australian, American and mixed-fleet equipment is covered. Pack sizes range from single inserts through to bulk packs of 50 and 100, depending on the size.
Left-Hand Thread Insert (9/16-20 UNF)
We stock a genuine left-hand wire thread insert in 9/16-20 UNF x 1/2" — a specialised item for applications with a left-hand thread convention (some rotating shafts, and certain hardware designed to prevent loosening under reverse rotation). Confirm your host thread's hand before ordering, as left-hand and right-hand inserts are not interchangeable.
Keysert — Key-Locking Thread Repair
The Recoil Keysert (we stock the Light-duty M10-1.5 x 14mm) is a solid-body insert locked into the host material by keys driven into slots around its base, rather than relying on the coil-spring action of a wire insert. This gives higher resistance to pull-out and rotation under load, at the cost of a one-way installation — once the locking keys are driven home, the Keysert isn't designed to be removed intact. It's worth considering over a standard wire insert where the host material is soft, load is high, or vibration risks a wire insert working loose over time.
Spark Plug Thread Repair (M14 x 1.25)
Stripped spark plug threads in aluminium cylinder heads are one of the most common thread repair jobs in automotive and small-engine workshops. Our RC08140 kit-size pack (M14-1.25 x 3/4", pack of 100) supplies the correct insert for the standard M14 x 1.25 spark plug thread — pair it with the matching STI tap and installation tool to restore the head without pulling it for a helicoil-style repair or a full re-tap to oversize.
Material & Finish
Every insert in this collection is 304 stainless steel — the standard specification for wire thread inserts, giving good corrosion resistance and a hardness well above typical host materials like aluminium, mild steel and timber. We don't currently stock 316 stainless or Inconel insert variants; if your application needs a different material spec, get in touch and we'll help source it.
Sizing, Selection & Installation
To specify the right insert: confirm the nominal thread size and pitch (e.g. M10-1.5, or 3/8-16 UNC), the thread length needed (1D for harder hosts, up to 2D for softer materials such as aluminium or timber where more thread engagement is wanted), and the pack quantity that suits the job. For a repair, match the insert to the original bolt or stud thread size — the tapped hole is drilled and tapped oversize to suit the insert, not the original fastener.
Installing a wire thread insert requires an STI (Screw Thread Insert) tap specific to the insert size — this is a different tool from a standard tap, cutting a slightly larger thread to accept the coiled insert. Drill to the specified pilot size, tap with the STI tap, wind the insert in with an installation tool until it sits at or just below the surface, then snap off the installation tang on tanged inserts. Keyserts require their own installation sequence, including driving the locking keys — follow the kit instructions or ask our team for guidance.
Relevant Standards
Wire thread inserts of this coiled-wire type are manufactured to NASM8846 (the aerospace-industry specification for helical coil screw-thread inserts, formerly MIL-I-8846), which sets the dimensional tolerances that keep inserts interchangeable with standard STI taps across manufacturers. The metric parent threads the inserts present to the fastener follow standard tolerancing under ISO 965 (metric screw thread tolerances) and the equivalent Australian standard AS 1275 (Metric screw threads for fasteners). We only cite standards we've confirmed apply to this product type — if you need a specific compliance certificate for a project, contact us and we'll check with Recoil directly.
Applications
Threaded inserts from this range are used across general engineering and maintenance workshops for thread repair on machinery, plant and vehicle components; in automotive and small-engine repair for stripped spark plug threads and sump/casing threads in aluminium; and in fabrication and manufacturing wherever a soft or repeatedly-assembled host material needs a durable, reusable thread. If you're not sure which insert type or size suits your job, send us a photo of the damaged thread or the assembly drawing and we'll help you spec it.
Brand We Stock
Every product in this collection is genuine Recoil — see the full Recoil range for related thread repair products beyond this collection.
Companion Ranges
- Recoil — the complete Recoil thread repair range
- Taps — including STI taps for insert installation
- Threading — dies, thread gauges and related tools
- Cobalt Drill Bits — for drilling out damaged threads before repair
- Extraction & Removal Tools — for broken bolts, studs and taps
- Fasteners — bolts, studs and nuts to pair with your repaired thread
Order From AIMS
Need help matching an insert to a stripped or damaged thread, or pricing a bulk quantity for production? Call our team on (02) 9773 0122, contact us online, or request a quote and we'll get back to you with sizing and stock advice — Industrial Supplies made Simple.
FAQs — Threaded Inserts
What is a threaded insert used for?
A threaded insert is fitted into a tapped oversize hole to repair a stripped thread or to create a strong, durable thread in a material that's too soft to hold one directly — aluminium, cast iron, timber and similar. It's also used where a joint will be assembled and disassembled many times, since the insert protects the host material from wear.
What sizes does AIMS stock threaded inserts in?
Our Recoil wire thread insert range covers metric M3-0.5 through to M24-3 (in 1D, 1.5D and 2D lengths), UNC from #10-24 to 7/8-9, and UNF from #10-32 to 3/4-16, all in 304 stainless steel and various pack quantities.
What's the difference between a wire thread insert and a Keysert?
A wire thread insert is a coiled spring-section wire that grips the host thread along its length. A Keysert is a solid-body insert locked in place by keys driven into the base material, giving higher resistance to pull-out and rotation — but it's a one-way installation, unlike a free-running wire insert.
Do you stock left-hand threaded inserts?
Yes — we stock a 9/16-20 UNF x 1/2" left-hand wire thread insert. Confirm the thread hand of your application before ordering, as left- and right-hand inserts aren't interchangeable.
What material are AIMS's threaded inserts made from?
All inserts in this range are 304 stainless steel, the standard material for wire thread inserts, offering good corrosion resistance and hardness well above typical host materials.
Do I need a special tap to install a wire thread insert?
Yes. Wire thread inserts require an STI (Screw Thread Insert) tap sized specifically for the insert — this cuts a slightly oversized thread to accept the coil. It's a different tool from a standard tap of the same nominal size.
Are Recoil inserts the same as Helicoil inserts?
They're the same technology — coiled stainless steel wire thread inserts manufactured to the same NASM8846 dimensional standard, so they're generally dimensionally interchangeable with the same STI tap sizes. Recoil and Helicoil are different manufacturers' brand names for the same product type. AIMS stocks genuine Recoil.
What is a spark plug thread repair insert used for?
It repairs a stripped M14 x 1.25 spark plug thread in an aluminium cylinder head, avoiding the cost and downtime of head removal or replacement. We stock the Recoil M14-1.25 x 3/4" spark plug insert for this job.
Can a threaded insert be removed once it's installed?
Free-running wire inserts can be removed with a dedicated extraction tool if needed. Keyserts are not designed to be removed intact once the locking keys are driven in — treat that installation as permanent.
What standard governs wire thread insert dimensions?
Wire thread inserts are manufactured to NASM8846 (formerly MIL-I-8846), which sets the dimensional tolerances ensuring the insert is compatible with the corresponding STI tap size.
How do I choose the right insert length?
Insert length is specified as a multiple of the thread diameter (1D, 1.5D or 2D). Shorter lengths suit harder host materials; longer inserts spread load over more thread engagement and suit softer materials such as aluminium or timber, or higher-load joints.
Can I order threaded inserts in bulk for production use?
Yes — most sizes in this range are available in multiple pack quantities up to 100, and we can arrange larger production quantities on request. Request a quote with your size and volume and we'll get back to you.