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Carmex Thread Turning External Insert - API 503 - Right Hand - 27ER4API503BMA
| Thread Type | External |
| Thread Direction | Right Hand |
| Thread Form | API 503 |
| Pitch | 4 |
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Description
Carmex Thread Turning External Insert - API 503 - Right Hand (27ER4API503BMA) is a versatile threading insert optimized for external thread turning. Its laydown triangular geometry is designed to cover a broad range of thread standards, helping you complete more jobs with fewer inserts and less setup.
Engineered for both professional shops and hobbyist workbenches, this insert delivers reliable, repeatable results—from basic threads to more demanding applications—so you can keep your workflow productive and on schedule.
- Broad thread compatibility: Covers the majority of thread standards in one tool, reducing the need for frequent insert changes and speeding up setup for mixed jobs.
- Triangular laydown geometry for stable cutting: The laydown triangle provides solid seating in your holder and delivers smooth chip control, helping you achieve consistent thread profiles across passes.
- Durable edge geometry for reliable performance: Designed to resist wear and maintain precision over many cycles, delivering repeatable results across a range of materials and feeds.
This insert helps you streamline threading workflows by minimizing tool changes, shaving cycle times, and delivering consistent, accurate external threads. Whether you’re manufacturing parts, performing quick repairs, or stocking a reliable supply in a busy workshop, this Carmex insert offers dependable performance you can trust job after job.
Part Numbers
- Protool Part Number
- 27ER4API503BMA
- 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.
