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Carmex Thread Turning Internal Insert - UN (UNC,UNF,UNEF,UNS) - Right Hand - 27IR4UNK20
| Thread Type | Internal |
| Thread Direction | Right Hand |
| Thread Form | UN (UNC UNF UNEF UNS) |
| Pitch | 4 |
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Description
The Carmex Thread Turning Internal Insert, Right Hand, model 27IR4UNK20, is a precision tool designed for cutting internal threads in UNC, UNF, UNEF, and UNS forms. It’s ideal for engineers, machinists, repair shops, and maintenance teams seeking fast, reliable internal threading with consistent results.
As part of Carmex's globally recognized range of thread turning inserts, this laydown triangular insert covers a broad spectrum of thread standards and applications—from basic pilot runs to the most demanding production tasks. Its design emphasizes durability and steady performance across materials and tolerances.
- Wide UN thread compatibility: Covers UNC, UNF, UNEF, and UNS internal threads with a single insert, reducing tool changes and simplifying inventory.
- Laydown triangular design for stable cutting: Optimized geometry delivers smooth cutting action, reduces vibration, and promotes consistent thread finish across materials.
- Right-hand orientation for reliable results: Specifically optimized for right-hand internal threads, enabling straightforward setup and repeatable performance from basic to demanding applications.
Using this insert helps you complete internal threading tasks more efficiently, maintain consistent thread quality, and extend tool life—leading to smoother workflows, reduced downtime, and dependable results across production runs and repair work.
Part Numbers
- Protool Part Number
- 27IR4UNK20
- Brand
- Carmex
- Category
- Thread Turning
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.
