Please log in here to access all benefits, including promotional discounts and faster checkouts.

Carmex Vertical Milling CMT Three Flute Insert - Threading - C251/4RDMT7
| Application | Threading |
| Thread Form | Round- DIN 407 |
| Internal or External | Internal |
| Insert Diameter | 25 |
| Pitch | 4 |
| Number of Flutes | 3 |
Learn more about Klarna
The Carmex Vertical Milling CMT Three Flute Insert – Threading (C251/4RDMT7) is a versatile, indexable insert designed for vertical milling applications. It excels at producing threads, grooves, chamfers and more with consistent results, making it suitable for engineers, machinists, tradespeople, and hobbyists who value reliable performance.
Built around a ground profile, this CMT threading insert delivers high precision and a smooth surface finish even when you push cutting parameters. Its solid and accurate clamping method ensures full repeatability across multiple parts, so you can count on repeatable results job after job. The same insert supports right-hand or left-hand threading, simplifying stocking and setups, and the toolholders include a weldon shank and coolant bore for practical, integrated use. Chamfer inserts are also available if you need to add finishing features in the same setup.
- Ground profile for high precision: Delivers tight tolerances and high-quality surfaces during threading and grooves, even at higher cutting parameters.
- Solid, repeatable clamping: Provides reliable workholding and full repeatability across parts and setups.
- Versatile threading and accessories: One insert handles both right- and left-hand threads, with weldon shank toolholders and coolant bore, and chamfer inserts available for streamlined setups.
This combination of precision geometry, reliable clamping, and universal threading capability helps you complete threaded, grooved, and chamfered features in fewer setups with consistent quality. By reducing tool changes and enabling standardization across jobs, it speeds up workflows and improves finish quality, giving you predictable results and greater confidence in every part you ship.
| Application | Threading |
| Thread Form | Round- DIN 407 |
| Internal or External | Internal |
| Insert Diameter | 25 |
| Pitch | 4 |
| Number of Flutes | 3 |
| Holder Code | H10 11 24 25 |
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 Vertical Milling CMT Single Flute Inserts - Round DIN 405
View full collection →You are viewing C251/4RDMT7. Click any other SKU to view its full details.
| Product SKU | Insert Size | Pitch | Price | Stock | Order |
|---|---|---|---|---|---|
| C181/6RDMT7 | 17.8 | 6 | £42.14 | In Stock | |
| C181/8RDMT7 | 17.8 | 8 | £42.14 | In Stock | |
| C251/4RDMT7 Viewing | 25 | 4 | £47.10 | 5 days |
No products match your filters.


