Please log in here to access all benefits, including promotional discounts and faster checkouts.
Carmex Thread Turning Holder 3.5 Helix Angle - Internal - Right Hand - 170mm OAL - 16IR Insert - 20 Shank Size
| Type | 3.5 Helix Angle |
| Internal or External | Internal |
| Minimum Bore | 19 |
| Shank Size | 20 |
Learn more about Klarna
Compatible inserts
The ones our customers buy most.
Description
Carmex Internal Thread Turning Holder with a 3.5° helix angle is a precision tool designed for machinists who need dependable internal threading on cylindrical parts. Built for right-hand internal threads, it delivers clean, repeatable results in automotive, aerospace, and general manufacturing applications.
- 3.5° helix angle: Optimizes chip flow and reduces cutting forces during internal threading to improve surface finish and tool life.
- Internal thread turning holder: Specifically engineered for internal threading with a secure insert seat and reliable alignment.
- Right-hand configuration: Designed for RH threading operations, ensuring correct cutting direction and thread form.
- 170 mm overall length (OAL): Extended reach provides access to deeper holes while maintaining rigidity and stability.
- 16IR insert interface: Uses Carmex 16IR inserts for standard internal thread profiles and consistent chip control.
- 20 mm shank size: Compatible with common toolholders and interface pockets for efficient setup and changes.
The combination of a controlled helix angle and a sturdy, long-reaching holder delivers precise, reproducible internal threads with better surface quality and reduced chatter. The 16IR insert option covers a wide range of common thread pitches, while the 20 mm shank and RH orientation align with typical production workflows, helping you shorten cycle times and improve part-to-part consistency. Ideal applications include threading in engine blocks, hydraulic housings, gear housings, and other deep-bore or pocketed components where tight tolerances matter.
Part Numbers
- Protool Part Number
- SIR0016P16B-3.5
- Brand
- Carmex
- Category
- Thread Turning
Need cutting data? Call 01732 887334 or email sales@protool-ltd.co.uk.
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.
