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Carmex Thread Mills Solid Carbide - Fast Type - For Hard Materials - UN (UNC UNF UNEF UNS) - 5/16, 3/8 x 24 - MT3

SKU:FSH08066F1624UNMT3

Engineered as an evolution of Carmex’s MTSH line, the FSH solid carbide thread mills deliver precise internal threading in the toughest materials. Designed for machinists who demand stability, we... Read more ↓
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Thread FormUN (UNC UNF UNEF UNS)
Size5/16 3/8
Pitch24
Diameter (D)6.6
Flute Length (l)3.18
Shank Diameter (d)8
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£110.83
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5 days estimated lead time — subject to availability
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Mon – Thurs 8:30 – 17:30 · Fri 8:30 – 16:30

Engineered as an evolution of Carmex’s MTSH line, the FSH solid carbide thread mills deliver precise internal threading in the toughest materials. Designed for machinists who demand stability, wear resistance, and fast cutting in hard alloys, this tool excels where others struggle.

  • Threading capacity: Compatible with UNC/UNF/UNEF/UNS threads in 5/16" and 3/8" sizes with 24 TPI for accurate, repeatable internal threads.
  • Material & shank: Solid carbide construction with an MT3 shank for rigid performance in CNC machines.
  • Flute design: Multi-flute geometry with up to 7 flutes (varies by size) to improve rigidity, chip evacuation, and surface finish when machining hard materials.
  • Coating: Ultra-fine grade with a PVD multi-layer coating that enhances heat resistance and wear life when cutting materials up to 65 HRC.
  • Fast-type cutting: Optimized geometry for efficient material removal without sacrificing edge stability or thread accuracy.

This thread mill is purpose-built for demanding applications, such as internal threads in hardened steels and challenging alloys. The high flute count, robust carbide substrate, and durable coating work together to extend tool life, reduce downtime, and deliver consistent thread quality across batches. Whether you're manufacturing tools, dies, or precision fasteners, this Carmex FSH tool helps you achieve reliable results with fewer passes and tighter tolerances.

Thread Form UN (UNC UNF UNEF UNS)
Size 5/16 3/8
Pitch 24
Diameter (D) 6.6
Flute Length (l) 3.18
Shank Diameter (d) 8
No of Flutes 6
Overall Length (L) 64
Thread Mill Style Mini (Fast)
Internal or External Internal
Coating MT3

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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honest about stock and prices are competitive.
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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 Thread Mills - UN - Mini Type For Hard Materials Up To 65HRC (FSH)

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You are viewing FSH08066F1624UNMT3. Click any other SKU to view its full details.

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