Recoil Thread Repair Quick Reference — Sizes & Kits
Recoil thread inserts are pre-wound 304 stainless steel coils used to restore stripped, cross-threaded or worn tapped holes. Available in metric, UNC, UNF, BSP and BSW thread forms. A Recoil insert produces a thread that is OFTEN STRONGER than the parent material — critical for aluminium and cast iron components subject to repeated assembly/disassembly. Full repair kits include the insert tap, pre-wound inserts, installation tool and break-off tool.
| Thread Form | Stocked Size Range | Common Workshop Sizes | Typical Repair Application |
|---|---|---|---|
| Metric Coarse | M3 - M24 | M6, M8, M10, M12 | Spark plug holes, aluminium engine blocks, gearbox housings, alloy fittings |
| Metric Fine | M6×1.0 - M24×2.0 | M8×1.0, M10×1.25, M12×1.25 | Hydraulic fittings, fine-pitch alloy fasteners |
| UNC (Unified Coarse) | #4-40 - 1"-8 | 1/4"-20, 5/16"-18, 3/8"-16 | US-origin machinery, automotive imports, older industrial equipment |
| UNF (Unified Fine) | #10-32 - 1"-12 | 5/16"-24, 3/8"-24, 7/16"-20 | Aerospace, fine-pitch automotive, precision threaded assemblies |
| BSP (Pipe Thread) | 1/8 - 1" | 1/8, 1/4, 3/8, 1/2 | Hydraulic and pneumatic pipe fittings, instrument connections |
| BSW (Whitworth) | 1/8 - 1" | 1/4, 5/16, 3/8 | Older Australian/UK machinery, vintage equipment restoration |
Each kit contains the matching insert tap (slightly oversize vs the original thread), pre-wound inserts, installation tool and break-off tool — ready to use without separate purchases. For application technique and when to use a thread insert vs alternative repair methods (Heli-Coil, time-sert, oversize plug), call (02) 9773 0122. Companion ranges: taps, tap wrenches.
Recoil Thread Repair Kits & Inserts
Recoil is Australia's leading brand for precision thread repair and thread insert solutions, trusted by maintenance engineers, mechanics and machinists across mining, manufacturing, defence and heavy industry. When a tapped thread is stripped, cross-threaded or damaged, a Recoil insert restores it to full original strength — often stronger than the parent material — without the need to replace the entire component. The Recoil system covers metric, UNC, UNF, BSP and BSW thread forms in 304 stainless steel inserts, with complete kits including the pre-wound inserts, installation tap, insertion tool and break-off tool ready to use straight from the box.
Recoil Thread Repair Kits — Metric, UNC, UNF & BSP
Each Recoil thread repair kit contains everything required to repair a single thread size: the correct size insert tap to cut the new thread, a pre-wound coil of 304 stainless steel inserts, the installation tool and break-off tool. Kits are available in all major thread forms to suit both metric and imperial fastener standards common in Australian plant, mining equipment, heavy vehicles and machinery. For sites requiring repair across a range of thread sizes, Recoil Range Kits bundle multiple sizes in a single case.
- Recoil Thread Repair Kit — Metric, 304 Stainless Steel: Complete metric thread repair kit for restoring stripped or damaged metric threads; includes insert tap, 304 stainless inserts, insertion and break-off tools
- Recoil Thread Repair Kit — UNC, 304 Stainless Steel: Unified coarse thread repair kit for UNC fastener standards common in North American and mining equipment
- Recoil Thread Repair Kit — UNF, 304 Stainless Steel: Unified fine thread kit for precision assemblies, hydraulics and applications where vibration resistance is critical
- Recoil Thread Repair Kit — BSP, 304 Stainless Steel: British Standard Pipe thread repair for hydraulic fittings, pneumatic connections and fluid system components
- Recoil RC35005R Range Kit — Metric M6–M16: Multi-size metric range kit covering M6 to M16; ideal for maintenance workshops dealing with a variety of metric thread sizes across plant and equipment
Recoil Inserts, Taps, Spark Plug Kits & Extraction Tools
For ongoing maintenance programmes, Recoil insert refill packs and individual component taps keep workshop stock replenished without buying complete kits. The Recoil spark plug kit range addresses one of the most common engine repair tasks — restoring stripped spark plug threads in aluminium cylinder heads without removing the head. The Keysert system provides a heavy-duty alternative to standard coil inserts where maximum thread strength is critical. The insert extraction tool handles the rare case where a previously installed insert needs to be removed.
- Recoil Insert — Metric, 304 Stainless Steel (Refill Pack): Bulk refill packs of metric stainless steel inserts for high-volume maintenance workshops; available across the full metric thread size range
- Recoil Metric Insert Tap — Bottoming: Bottoming tap for use in blind holes where full thread depth to the bottom of the hole is required; precision-ground for accurate thread preparation
- Recoil Metric Insert Tap — Intermediate: General-purpose intermediate tap for through holes and deeper blind holes in standard thread repair operations
- Recoil RC38148 Plug Saver Kit M14-1.25: Spark plug thread repair kit for M14-1.25 threads; repairs stripped spark plug holes in aluminium cylinder heads without head removal — a critical time-saving repair for workshop and field use
- Recoil Keysert Light — Metric Stainless Steel: Solid stainless steel keyed insert providing maximum thread strength; preferred over wire coil inserts in high-stress applications subject to heavy cyclic loading
- Recoil RC50003 Insert Extraction Tool M4–M24: Removal tool for extracting previously installed Recoil inserts from M4 to M24; essential for rework situations where insert removal is required
Browse Recoil thread repair kits & inserts at AIMS Industrial alongside our Hand Tools, Fasteners & Fixings, and Workshop Equipment collections.
Order online, Contact our team for assistance or to Request a quote.
People Also Ask — Recoil Thread Repair
Q: What's a Recoil thread repair insert?
Recoil is a coiled-wire thread insert that restores damaged threads to their original size — or upgrades a soft-material hole to a stronger steel thread. The insert sits inside a tapped hole, providing a wear-resistant steel thread for bolts to engage. Used to repair stripped threads in aluminium engine blocks, transmission housings, and any soft-metal threads. Recoil's 3 generations (original, Recoil Heli-Coil-compatible, Recoil Pro-Coil) cover most thread repair scenarios.
Q: How do I install a Recoil insert?
Four steps: (1) drill out damaged thread to specified diameter using Recoil's drill bit, (2) tap the hole with the matching STI (Screw Thread Insert) tap, (3) install insert using Recoil's insertion tool — it threads in and stops below the surface, (4) break off the insert tang using the tang break-off tool. Each kit specifies the drill, tap, and insertion tool sizes — don't substitute generic tools.
Q: Recoil vs Helicoil — are they compatible?
Recoil Heli-Coil-compatible inserts use the same drill/tap dimensions as Helicoil — direct replacement in existing Helicoil-tapped holes. Original Recoil inserts use a slightly different tap thread but install in their own drilled/tapped hole. If you have an existing Helicoil installation, use the Heli-Coil-compatible Recoil range. For new repairs, either system works — Recoil tends to be more available at AIMS. See our [Recoil 3-Generation Cross-Reference Guide](/blogs/product-guides/recoil-thread-repair-cross-reference-guide) for full RC code matching.
Q: What sizes does Recoil cover?
Recoil insert kits cover metric M3 through M30 and imperial #4-40 through 1" UNC/UNF — covering nearly all common workshop thread sizes. Length options typically 1×D, 1.5×D, 2×D, 2.5×D and 3×D (where D is the nominal thread diameter). Use longer inserts in softer parent material (aluminium needs 2-3×D) and shorter inserts in steel. The Recoil cross-reference covers all generations + sizes.
Q: Will a Recoil insert hold spark plug compression?
Yes — Recoil inserts are commonly used for spark plug thread repair in aluminium cylinder heads, holding combustion pressure reliably when correctly installed. Use the spark-plug-specific kit (different drill/tap dimensions to suit the spark plug seat). Install with thread-locker on the insert if specified by the kit. Tens of thousands of spark plug repairs use Recoil inserts daily — proven for high-cycle, high-temperature, high-pressure service.