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Carmex Carbide Threading Insert - UNJ - TiAlN Coated - 21E20UNJ

SKU:21E20UNJ

The Carmex Carbide Threading Insert for UNJ, TiAlN coated (model 21E20UNJ) is a versatile solution for precision threading across common profiles. Built for machinists and workshops that value co... Read more ↓
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M
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ApplicationThreading
Thread FormUNJ
Internal or ExternalExternal
Insert Size21
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£30.44
Prices shown ex. VAT
5 days estimated lead time — subject to availability
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Free delivery over £50 ex VAT
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14-day returns
30+ years expertise
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01732 887334
Mon – Thurs 8:30 – 17:30 · Fri 8:30 – 16:30

Description

The Carmex Carbide Threading Insert for UNJ, TiAlN coated (model 21E20UNJ) is a versatile solution for precision threading across common profiles. Built for machinists and workshops that value consistent performance and long tool life.

  • Material: Solid carbide substrate for rigidity and wear resistance in demanding threading operations.
  • Coating: TiAlN coating enhances hardness and heat resistance, helping maintain cutting efficiency during high-temperature threading.
  • Thread profiles: Covers all common thread profiles in one insert family, streamlining setup for diverse projects.
  • Lengths: Five lengths available, from 12 mm to 40 mm, to fit different hole depths and workpiece geometries.
  • Pitch range: Depending on length, capable of threading pitches from 0.5 mm (32 TPI) to 6.0 mm (4 TPI).
  • Double cutting edges: Inserts are double-sided with two cutting edges (except for BSPT/NPT/NPTF/American Buttress/API RD variants) for extended use between indexings.
  • Internal/External capability: For many thread profiles, the same insert can machine both internal and external threads, with exceptions for ISO/UN/NPSM/UNJ/Acme.
  • Designation: 21E20UNJ, a precise identifier to ensure you select the UNJ-specific variant.
  • Brand: Carmex, a trusted name in carbide tooling and threading solutions.

This insert is designed to deliver reliable thread quality with minimal tool changes thanks to its dual-edge design, while the TiAlN coating provides resilience under heat and friction. Its five length options let you tailor engagement and reach to your specific machining setup, helping you achieve consistent thread profiles across a variety of workpieces without inventory clutter. Ideal for shops performing both routine and mixed-threading tasks where durability and precision are essential.

Part Numbers

Protool Part Number
21E20UNJ
Brand
Carmex
Category
Thread Mill
Delivery

Free UK mainland delivery on orders over £50 ex VAT. In-stock items ordered before 4:30pm are dispatched the same working day. Full delivery information.

Returns

14-day returns on unused stock items in original packaging. Special-order and bespoke tooling is non-returnable. Read our returns policy.

Technical Support

Over 30 years of machining experience behind the counter. Call 01732 887334, Mon–Thurs 8:30–17:30, Fri 8:30–16:30.

Trade Accounts

Credit accounts, contract pricing and scheduled call-off orders available for trade customers. Apply for an account.

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.

Ask our technical team about this tool

Not sure if this is the right tool for your job? Ask us about speeds and feeds, material suitability, holders or alternatives — 30+ years of machining experience on the other end.

Prefer to talk? Call 01732 887334 — Mon–Thurs 8:30–17:30, Fri 8:30–16:30.

Full Range: Carmex Carbide Threading Inserts - UNJ - TiAlN Coated

View full collection →

You are viewing 21E20UNJ. Click any other SKU to view its full details.

Product SKUInsert SizePitchPriceStock Order
14I24UNJ 1424£22.91 5 days
14E24UNJ 1424£22.91 5 days
14I20UNJ 1420£22.91 5 days
14E20UNJ 1420£22.91 5 days
14I18UNJ 1418£29.81 In Stock
14E18UNJ 1418£22.91 5 days
14I16UNJ 1416£22.91 5 days
14E16UNJ 1416£22.91 5 days
14I14UNJ 1414£22.91 5 days
14E14UNJ 1414£22.91 5 days
14I12UNJ 1412£22.91 5 days
14E12UNJ 1412£22.91 5 days
21I24UNJ 2124£30.44 5 days
21E24UNJ 2124£30.44 5 days
21I20UNJ 2120£30.44 5 days
21E20UNJ Viewing2120£30.44 5 days
21I18UNJ 2118£30.44 5 days
21E18UNJ 2118£30.44 5 days
21I16UNJ 2116£30.44 5 days
21E16UNJ 2116£30.44 5 days
21I14UNJ 2114£30.44 5 days
21E14UNJ 2114£30.44 5 days
21I12UNJ 2112£39.62 In Stock
21E12UNJ 2112£30.44 5 days

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