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Carmex Single Long Shank Threading Insert holder - For Carbide External/Internal Threading Inserts - SR0025K21

SKU:SR0025K21

Carmex SR0025K21 is a dedicated long shank threading insert holder designed for carbide external and internal threading inserts. Built for CNC milling environments, it unlocks extended reach on l... Read more ↓
Insert Size21
Shank Diameter20
Shank MaterialSteel
ReachStraight Shank
Overall Length125
Minimum Bore Diameter25
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£140.66
Prices shown ex. VAT
5 days estimated lead time — subject to availability
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Carmex SR0025K21 is a dedicated long shank threading insert holder designed for carbide external and internal threading inserts. Built for CNC milling environments, it unlocks extended reach on long overhang threading tasks without sacrificing accuracy or reliability.

  • Long overhang design: A purpose-built tool holder line for applications requiring extended reach in threading projects.
  • Internal coolant bore: Integrated coolant channel helps flush chips, improve insert life, and maintain steady cutting performance.
  • Maximum length: Supports substantial reach with an overall holder length up to 210 mm (6 inches) for versatile setups.
  • Carbide insert compatibility: Optimized to hold carbide external and internal threading inserts for multi-tooth, high-efficiency cutting.
  • Cost-efficient solution: More economical than taps and dies for long-threading tasks, while delivering reusable inserts and repeatable results.
  • Machining method: Designed to work with CNC milling machines using helical interpolation programs to achieve precise thread milling.
  • Model: SR0025K21

This holder is crafted to boost productivity in thread milling jobs by enabling higher cutting speeds with multi-tooth carbide inserts, while maintaining consistent thread quality. It’s especially valuable for shops tackling long, deep, or hard-to-reach threads where traditional tapping isn’t practical. When working with long overhangs, lightly reduce cutting speed and feed rate by 20–40%—the exact adjustment depends on workpiece material, thread pitch, and the degree of overhang—to preserve tool life and finish. Use the Carmex long shank threading insert holder to streamline setups, extend tool life, and achieve reliable, precise threads on CNC mills.

Insert Size 21
Shank Diameter 20
Shank Material Steel
Reach Straight Shank
Overall Length 125
Minimum Bore Diameter 25
Flutes 1
Insert Screw S21
Torx Key K21
Extension N/A

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 polite.Goods that were in stock were dispatched same day and back orders were quick in coming through .
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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 Single Long Shank Threading Insert holders - For Carbide External/Internal Threading Inserts

View full collection →

You are viewing SR0025K21. Click any other SKU to view its full details.

Product SKUInsert SizeShank DiameterReachOverall LengthMinimum Bore DiameterPriceStock Order
SR0025K21 Viewing2120Straight Shank12525£140.66 5 days
SR0031M30 3025Straight Shank15031£159.62 5 days
SR0038M30 3032Straight Shank15038£166.00 5 days
SR0048R40 4040Straight Shank21048£244.30 5 days

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