Metric Thread Repair Kits for M3–M12 Thread Repair
Metric thread repair kits restore damaged internal threads in M-series holes such as M3, M4, M5, M6, M8, M10 and M12. A complete kit should match the insert, drill preparation, STI tap, installation tool, tang-removal method and packaging.
Taiyi supplies single-size metric kits, multi-size assortments, refill insert packs and private-label kit programs for distributors, workshops, maintenance teams and OEM after-sales supply.
First confirm the metric size and pitch, insert length, complete-kit or refill-pack format, insert count, tool configuration and packaging. “M6 kit” alone is not enough to quote accurately.
Types of Metric Thread Repair Kits
Separate complete repair kits from refill consumables. The distinction affects pricing, packaging and end-user expectations.
Single-Size Kit
One exact thread such as M6 × 1.0 or M8 × 1.25, normally with inserts and the matched repair tools.
Metric Assortment
Multiple M-sizes in one case for workshops, maintenance teams and distributor ranges.
Refill Insert Pack
Replacement inserts only for users who already own the correct drill, STI tap and installation tools.
Common Sizes for Metric Thread Repair Kits
The values below define the product family, not universal drill dimensions. Confirm pitch and approved STI drill data before packing or repair.
| Size | Typical Kit Position | Buyer Must Confirm | Typical Market Use |
|---|---|---|---|
| M3–M4 | Small precision or light-duty kits. | Pitch, insert length, small-tool handling and insert count. | Electronics, panels, brackets and compact housings. |
| M5 | General maintenance and resale size. | Pitch, tool matching, insert length and pack format. | Fixtures, machinery and repair assortments. |
| M6 | Common single-size repair kit. | Common pitch, drill, STI tap, tool, insert count and label. | Automotive, machinery, aluminum and steel components. |
| M8 | Workshop and distributor core size. | Kit completeness, insert length, tool durability and case layout. | Vehicle, machine and equipment maintenance. |
| M10–M12 | Larger industrial repair kits. | Hole depth, load, insert length, STI tap quality and tool format. | Castings, heavy machinery and larger housings. |
What Complete Metric Thread Repair Kits Should Include
| Component | Function | Buyer Check | Mismatch Risk |
|---|---|---|---|
| Wire Thread Inserts | Create the finished metric internal thread. | M-size, pitch, length, free-running/locking, tanged/tangless and quantity. | Wrong pitch or length makes the kit unusable. |
| Drill Bit | Prepares the damaged hole for STI tapping. | Approved diameter, material capability and hole depth. | Oversize or undersize hole causes installation failure. |
| STI Tap | Creates the special insert installation thread. | Metric size, pitch, through/blind-hole use and tap style. | A standard tap cannot replace an STI tap. |
| Installation Tool | Installs the insert to the required depth. | Mandrel, prewinder, tanged/tangless type and size. | Wrong tool can stretch or damage the insert. |
| Tang-Break Tool | Removes the tang for tanged inserts when required. | Insert size, access and loose-tang control. | An incomplete repair workflow reaches the customer. |
| Case and Labels | Organize tools and support resale or field service. | Size, pitch, contents, barcode, logo, language and instructions. | Mixed components and customer complaints. |
Choosing Metric Thread Repair Kits, Assortments or Refill Packs
Choose a Complete Kit
- The user does not own matched tools.
- Repair must be portable or field-ready.
- The product is sold as a finished retail or industrial set.
Choose an Assortment
- Several metric sizes are repaired regularly.
- A workshop needs one controlled case.
- The distributor has demand across multiple M-sizes.
Choose Refill Packs
- The installed tool system is already proven.
- Only consumable inserts require replenishment.
- Insert size, pitch, length and type are controlled.
Metric Thread Repair Kits RFQ Checklist
Thread Details
- Metric size and pitch.
- Insert length: 1D, 1.5D, 2D or other.
- Free-running or screw-locking.
- Tanged or tangless.
- Quantity by size.
Kit Details
- Complete kit, assortment or refill pack.
- Insert count per kit.
- Drill and STI tap requirement.
- Installation tool and tang breaker.
- Extractor and spare parts.
Commercial Details
- Sample and bulk quantity.
- Case, box or bulk packaging.
- Neutral or private label.
- Barcode, artwork and manual.
- Target market and delivery plan.
How to Build a Reliable M3–M12 Kit Range
Metric thread repair kits should be planned from actual repair demand rather than filling a case with as many sizes as possible. Each size needs the correct pitch, insert length, drill preparation, STI tap, installation tool and refill logic.
Core Size Planning
M5, M6, M8, M10 and M12 are common industrial repair directions, but local machinery, automotive and maintenance demand should determine the final range. M3 and M4 may be useful for compact assemblies, while fine-pitch sizes should be added only after demand is confirmed.
Pitch Control
Metric size alone is incomplete. M8, M10 and M12 may be requested in coarse or fine pitches. The case label, insert bag, STI tap and drill reference must all identify the same pitch to prevent mixed kits.
Length Control
Insert lengths such as 1D, 1.5D and 2D serve different engagement requirements. A kit should not mix lengths without clear labeling because the user may install an insert that is too short or too long for the prepared hole.
Metric Thread Repair Workflow
A complete kit should support the entire repair sequence. The user should not discover after drilling that the supplied tap, tool or insert belongs to a different system.
Identify
Confirm the original metric thread, pitch, damage, hole type and available depth.
Prepare
Use the approved STI tap drill reference and keep the hole aligned with the original thread axis.
STI Tap
Create the special installation thread using the matching metric STI tap.
Install
Drive the insert with the correct mandrel or prewinder to the specified depth.
Inspect
Remove the tang when required and verify depth, cleanliness and screw engagement.
Common Metric Kit Specification Errors
Wrong Pitch in the Same Case
A correctly labeled insert can still fail if the drill reference, STI tap or installation tool belongs to another pitch. The complete component chain must be checked before packing.
Incomplete Tool Set
Some low-cost kits omit a tang breaker, extractor or clear installation instructions. The quotation should state exactly what is included and what the end user must supply separately.
Uncontrolled Refill Packs
Refill inserts should reference the original kit size, pitch, length and insert type. Generic refill labeling increases the risk of mixing free-running, locking or different-length inserts.
Case Layout without Identification
A multi-size assortment needs permanent size and pitch identification inside the case. Loose labels or similar-looking tools can lead to cross-use between M6, M8 and other sizes.
Drill Data Treated as Universal
The approved drill preparation should follow the selected insert system and supplier data. Do not assume that every kit sold under the same nominal M-size uses identical preparation dimensions.
No Sample Approval
For distributor and private-label orders, approve the insert, tools, case, contents list, barcode and instructions before producing the full quantity.
Quality and Packaging Checks for Bulk Orders
| Check | What to Review | Why It Matters | Approval Evidence |
|---|---|---|---|
| Insert Identification | Size, pitch, length, type and quantity. | Prevents mixed refill packs and wrong repairs. | Approved label and sample pack. |
| Tool Matching | Drill, STI tap, mandrel, tang breaker and extractor. | Confirms that the kit supports the full process. | Trial installation with the sample kit. |
| Case Layout | Tool retention, size positions, insert compartments and contents list. | Reduces shipping damage and field confusion. | Case photograph and physical sample. |
| Private Label | Logo, barcode, language, warning, manual and country requirements. | Prevents artwork changes after production starts. | Signed artwork and packing specification. |
| Refill Compatibility | Replacement insert SKU linked to the original kit. | Supports repeat sales and reduces support problems. | Controlled refill list by size and length. |
FAQ: Metric Thread Repair Kits
What is included in metric thread repair kits?
A complete kit can include inserts, drill bit, STI tap, installation tool, tang-break tool and case. Exact contents must be confirmed by size and buyer requirement.
Is a refill pack the same as a complete kit?
No. A refill pack normally contains inserts only and assumes the user already owns the matched repair tools.
Do metric wire insert kits require STI taps?
Yes. Wire inserts require a matching STI installation thread. A normal tap is not an acceptable substitute.
Can Taiyi supply private-label metric kits?
Private-label programs can be reviewed from the size list, insert counts, tool configuration, case, label, barcode, manual, sample order and bulk quantity.
Need Metric Thread Repair Kits or Refill Packs?
Send the size list, pitch, insert length, kit format, tool contents, packaging and quantity.