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Carmex Carbide Threading Insert - Unified - TiAlN Coated - 21I12UN
| Application | Threading |
| Thread Form | UN |
| Internal or External | Internal |
| Insert Size | 21 |
| Pitch | 12 |
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The Carmex Carbide Threading Insert - Unified - TiAlN Coated - 21I12UN is a versatile, ready-to-use threading solution designed for professional machinists who need reliable performance across standard thread profiles on CNC lathes and manual machines.
- TiAlN-coated carbide substrate: Durable coating that enhances wear resistance and high-temperature performance for consistent threading results.
- Unified threading coverage: A single insert family that supports all common thread profiles, simplifying tool selection and inventory.
- Five length options: Available in 12 mm, 16 mm, 20 mm, 32 mm, and 40 mm lengths to fit different toolholders and reach requirements.
- Pitch range supported: Depending on length, handles pitches from 0.5 mm (32 TPI) up to 6.0 mm (4 TPI) for a broad range of thread forms.
- Double-sided cutting edges: Two cutting edges per insert to maximize usable life; note exceptions for BSPT, NPT, NPTF, American Buttress, and API RD profiles where a single edge is used.
- Internal and external threading capability: For many profiles, the same insert can machine both internal and external threads, reducing tool changes—with noted exceptions for ISO, UN, NPSM, UNJ, and Acme profiles.
- Model and compatibility: 21I12UN designation identifies the unified, TiAlN-coated threading insert family from Carmex.
With the TiAlN coating and a carbide foundation, this insert delivers precise thread forms at higher speeds while maintaining durability. The dual-edge design helps extend usable life between changes, and the unified profile coverage reduces the need for multiple inserts. Its capability to machine both internal and external threads in many profiles saves setup time and simplifies tooling workflows, making it a practical choice for job shops, contract manufacturers, and in-house machining teams that handle a variety of threading projects. The five length options let you tailor rigidity and reach to your machine setup, ensuring clean, accurate threads across a wide range of materials.
| Application | Threading |
| Thread Form | UN |
| Internal or External | Internal |
| Insert Size | 21 |
| Pitch | 12 |
What time are Protool open?
We are open Monday to Friday between 8:30am and 5pm.
Do you offer Free Next Day delivery?
Yes! We offer Free Next Day delivery via Royal Mail Tracked 24 on all orders over £50 ex VAT*. We also offer Free DPD Local Next Day delivery on all orders over £100 ex VAT*.
We also offer the following:
- Royal Mail Tracked 24 — £5.90 (FREE on orders over £50 ex VAT*). Order before 4:30pm for next day delivery. No signature required.
- DPD Local Next Day — £8.00 (FREE on orders over £100 ex VAT*). Standard next day delivery to UK mainland addresses.
- Royal Mail Special Delivery — £12.50. Guaranteed delivery before 1pm the next working day.
- DPD Saturday Delivery — £25.00. Must be ordered on Friday before 4pm. Pre-12pm delivery.
For delivery to Scottish Highlands & Islands, Northern Ireland, Republic of Ireland, or overseas locations, additional charges apply. Please see our delivery page for full details, or call us on 01732 887 334.
*T's & C's and exclusions apply. Please see our delivery page for more information on all our services.
Full Range: Carmex Carbide Threading Inserts - Unified - TiAlN Coated
View full collection →You are viewing 21I12UN. Click any other SKU to view its full details.
| Product SKU | Insert Size | Pitch | Price | Stock | Order |
|---|---|---|---|---|---|
| 12I16UN | 12 | 16 | £26.50 | In Stock | |
| 12I18UN | 12 | 18 | £26.50 | 5 days | |
| 12I20UN | 12 | 20 | £26.50 | In Stock | |
| 12I24UN | 12 | 24 | £26.50 | 5 days | |
| 12I28UN | 12 | 28 | £26.50 | In Stock | |
| 12I32UN | 12 | 32 | £26.50 | In Stock | |
| 14E10UN | 14 | 10 | £32.37 | 5 days | |
| 14E11UN | 14 | 11 | £32.37 | 5 days | |
| 14E12UN | 14 | 12 | £26.50 | In Stock | |
| 14E14UN | 14 | 14 | £26.50 | In Stock | |
| 14E16UN | 14 | 16 | £26.50 | In Stock | |
| 14E18UN | 14 | 18 | £26.50 | 5 days | |
| 14E20UN | 14 | 20 | £26.50 | In Stock | |
| 14E24UN | 14 | 24 | £26.50 | In Stock | |
| 14E28UN | 14 | 28 | £26.50 | In Stock | |
| 14E32UN | 14 | 32 | £26.50 | 5 days | |
| 14I10UN | 14 | 10 | £26.50 | In Stock | |
| 14I11UN | 14 | 11 | £26.50 | In Stock | |
| 14I12UN | 14 | 12 | £26.50 | In Stock | |
| 14I14UN | 14 | 14 | £26.50 | 5 days | |
| 14I16UN | 14 | 16 | £26.50 | In Stock | |
| 14I18UN | 14 | 18 | £26.50 | In Stock | |
| 14I20UN | 14 | 20 | £26.50 | In Stock | |
| 14I24UN | 14 | 24 | £26.50 | In Stock | |
| 14I27UN | 14 | 27 | £26.50 | In Stock | |
| 14I28UN | 14 | 28 | £26.50 | In Stock | |
| 14I32UN | 14 | 32 | £26.50 | In Stock | |
| 14I9UN | 14 | 9 | £26.50 | In Stock | |
| 21E10UN | 21 | 10 | £35.22 | 5 days | |
| 21E11UN | 21 | 11 | £43.03 | 5 days | |
| 21E12UN | 21 | 12 | £35.22 | 5 days | |
| 21E14UN | 21 | 14 | £35.22 | 5 days | |
| 21E16UN | 21 | 16 | £35.22 | In Stock | |
| 21E18UN | 21 | 18 | £35.22 | In Stock | |
| 21E20UN | 21 | 20 | £35.22 | In Stock | |
| 21E24UN | 21 | 24 | £35.22 | In Stock | |
| 21I10UN | 21 | 10 | £35.22 | In Stock | |
| 21I12UN Viewing | 21 | 12 | £35.22 | 5 days | |
| 21I14UN | 21 | 14 | £35.22 | In Stock | |
| 21I16UN | 21 | 16 | £35.22 | In Stock | |
| 21I18UN | 21 | 18 | £35.22 | In Stock | |
| 21I20UN | 21 | 20 | £35.22 | In Stock | |
| 21I24UN | 21 | 24 | £35.22 | In Stock | |
| 21I7UN | 21 | 7 | £35.22 | In Stock | |
| 21I8UN | 21 | 8 | £35.22 | In Stock | |
| 30E10UN | 30 | 10 | £48.30 | 5 days | |
| 30E12UN | 30 | 12 | £48.30 | 5 days | |
| 30E14UN | 30 | 14 | £48.30 | 5 days | |
| 30E16UN | 30 | 16 | £48.30 | 5 days | |
| 30E18UN | 30 | 18 | £48.30 | 5 days | |
| 30E20UN | 30 | 20 | £48.30 | 5 days | |
| 30E6UN | 30 | 6 | £48.30 | 5 days | |
| 30E8UN | 30 | 8 | £48.30 | 5 days | |
| 30I10UN | 30 | 10 | £48.30 | 5 days | |
| 30I12UN | 30 | 12 | £48.30 | In Stock | |
| 30I14UN | 30 | 14 | £48.30 | 5 days | |
| 30I16UN | 30 | 16 | £48.30 | 5 days | |
| 30I18UN | 30 | 18 | £48.30 | In Stock | |
| 30I20UN | 30 | 20 | £48.30 | 5 days | |
| 30I5UN | 30 | 5 | £48.30 | In Stock | |
| 30I6UN | 30 | 6 | £48.30 | 5 days | |
| 30I8UN | 30 | 8 | £48.30 | 5 days | |
| 40E10UN | 40 | 10 | £83.54 | 5 days | |
| 40E12UN | 40 | 12 | £83.54 | 5 days | |
| 40E14UN | 40 | 14 | £83.54 | 5 days | |
| 40E16UN | 40 | 16 | £83.54 | 5 days | |
| 40E6UN | 40 | 6 | £83.54 | 5 days | |
| 40E8UN | 40 | 8 | £83.54 | 5 days | |
| 40I10UN | 40 | 10 | £83.54 | 5 days | |
| 40I12UN | 40 | 12 | £83.54 | 5 days | |
| 40I14UN | 40 | 14 | £83.54 | 5 days | |
| 40I16UN | 40 | 16 | £83.54 | 5 days | |
| 40I4.5UN | 40 | 4.5 | £83.54 | 5 days | |
| 40I4UN | 40 | 4 | £83.54 | 5 days | |
| 40I6UN | 40 | 6 | £83.54 | 5 days | |
| 40I8UN | 40 | 8 | £83.54 | 5 days |
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