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Carmex Carbide Threading Insert - NPT - TiAlN Coated - 21-11.5NPT

SKU:21-11.5NPT

Introducing the Carmex Carbide Threading Insert for NPT, a TiAlN-coated carbide insert designed for professional threading tasks. Built for machinists and fabrication shops, it delivers precise, ... Read more ↓
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ApplicationThreading
Thread FormNPT
Internal or ExternalInternal & External
Insert Size21
Pitch11.5
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£38.88
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In Stock— only 3 left
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Introducing the Carmex Carbide Threading Insert for NPT, a TiAlN-coated carbide insert designed for professional threading tasks. Built for machinists and fabrication shops, it delivers precise, repeatable NPT and common-thread profiles with durable performance on both internal and external threads.

  • Coating: TiAlN coating enhances wear resistance and heat tolerance for longer tool life in demanding threading applications.
  • Material: Carbide substrate provides stiffness, sharpness, and consistent cutting action across different thread forms.
  • Model/Code: 21-11.5NPT, specifically tailored for NPT thread work and related profiles.
  • Length options: Five lengths available (12 mm to 40 mm) to fit various hole depths, collars, and shoulder constraints.
  • Pitch range: Compatible with pitches from 0.5 mm (32 TPI) to 6.0 mm (4 TPI), covering the most common threading needs.
  • Double-sided edges: Insert is double-sided with two cutting edges on most profiles, extending usage life (note: BSPT/NPT/NPTF/American Buttress/API RD may not use the second edge).
  • Internal/External threading compatibility: For many thread profiles, the same insert can machine both internal and external threads, reducing tool changes and inventory (with profile exceptions such as ISO/UN/NPSM/UNJ/Acme).

Designed for efficiency and reliability, this insert supports precise thread forms across a wide range of standard profiles while delivering the stability of TiAlN-coated carbide. It’s an excellent choice for pipe fittings, valves, housings, and other components where consistent thread quality and tool life matter—whether you’re setting up batch runs or performing quick-turn jobs.

Application Threading
Thread Form NPT
Internal or External Internal & External
Insert Size 21
Pitch 11.5

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.

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Staff are very helpful and interested in providing a good service making us the customer feel valued.
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Staff are very helpful and polite.Goods that were in stock were dispatched same day and back orders were quick in coming through .
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Buying experience
Phone requests are handled quickly and without any fuss. The website is easy to use and straightforward to order from. It’s especially helpful that it shows real‑time availability, so we don’t need to call to confirm whether parts will arrive.
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Full Range: Carmex Carbide Threading Inserts - NPT - TiAlN Coated

View full collection →

You are viewing 21-11.5NPT. Click any other SKU to view its full details.

Product SKUInsert SizePitchPriceStock Order
12-18NPT 1218£29.10 In Stock
14-14NPT 1414£29.10 In Stock
14-18NPT 1418£29.10 In Stock
21-11.5NPT Viewing2111.5£38.88 In Stock
21-14NPT 2114£38.88 In Stock
30-11.5NPT 3011.5£53.38 In Stock
30-8NPT 308£53.38 In Stock
40-11.5NPT 4011.5£91.88 5 days
40-8NPT 408£91.88 5 days

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