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Carmex Carbide Threading Insert - Unified - TiAlN Coated - 21E16UN
| Application | Threading |
| Thread Form | UN |
| Internal or External | External |
| Insert Size | 21 |
| Pitch | 16 |
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Carmex Carbide Threading Insert – Unified, TiAlN coated, 21E16UN is a versatile threading solution built for precision and reliability across common thread profiles. Designed for machinists and shops that need a single, robust insert capable of handling a range of internal and external threads, it delivers consistent results with minimal tool changes.
- Coating: TiAlN-coated carbide for improved wear resistance and heat handling, extending insert life in tougher cutting conditions.
- Threading coverage: Unified threading inserts that cover all the most common thread profiles, reducing the need to stock multiple inserts.
- Length options: Five lengths available (from 12 mm to 40 mm) to fit different tooling setups and depth requirements.
- Cutting edges: Double-sided design with two cutting edges per insert (except for BSPT/NPT/NPTF/American Buttress/API RD profiles), maximizing usable life.
- Internal/External capability: For many thread profiles, the same insert can machine both internal and external threads, reducing inventory and setup time (with exceptions for ISO/UN/NPSM/UNJ/Acme).
- Pitch range: Suitable for pitches from 0.5 mm (32 TPI) up to 6.0 mm (4 TPI), enabling a wide range of thread sizes.
- Series designation: 21E16UN, a unified system designation that supports consistent performance across common threading tasks.
This threading insert delivers practical value by combining durability, versatility, and efficiency. The TiAlN coating helps maintain dimensional accuracy and smooth surface finishes, while the dual-edged design and broad pitch range reduce tool changes and stocking needs. Ideal for workshops and production environments that require reliable, multi-profile threading performance without sacrificing precision or productivity.
| Application | Threading |
| Thread Form | UN |
| Internal or External | External |
| Insert Size | 21 |
| Pitch | 16 |
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 21E16UN. 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 Viewing | 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 | 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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