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Robert Charles Piloted Microstop Countersink - 3 Flute - Integral Pilot - Threaded Shank - 17mm Cutter Dia - 5/16 Pilot Diameter - 120°
| Pilot Diameter | 5/16 |
| Cutter Diameter | 17 |
| Inclusive Angle | 120 |
| Thread | M8X1 |
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Description
The Robert Charles Piloted Microstop Countersink is a precision tool designed for repeatable, accurately aligned countersinks in drilled holes. It features a 3-flute cutting design, an integral pilot, a 17 mm cutter diameter, and a 120° countersink angle, all compatible with microstop cages to maintain exact depth control. The tool is ideal for aerospace, automotive, and precision engineering tasks where consistent results and tight tolerances matter. The pilot diameter is specified as 5/16" and is manufactured to tight tolerances for high-accuracy work.
- Integral pilot with 3‑flute design: The built‑in pilot guides the countersink precisely into the hole while the 3 flutes deliver efficient material removal and a clean, uniform edge, reducing wandering and rework.
- Threaded shank for secure fitment and depth control: The threaded shank locks firmly in place and works seamlessly with depth‑control setups, ensuring stable operation and consistent countersink depth across parts.
- Tight-tolerance pilot diameter for repeatable accuracy: Pilot diameter held to −0.0005" to −0.0015" (5/16" nominal) delivers dependable center alignment and uniform countersinks, even in high‑accuracy aerospace and automotive applications.
Designed for demanding work streams, this countersink helps you achieve accurate, burr-free finishes with fewer cycles and less setup time. Its robust construction and precise tolerances translate to improved workflow efficiency, better part quality, and greater confidence in high-precision assemblies.
Part Numbers
- Protool Part Number
- S7.94-120-17
- Brand
- Robert Charles
- Category
- Countersinks
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.
Full Range: Robert Charles Piloted Microstop Countersink - 3 Flute - Integral Pilot - Threaded Shank
View full collection →You are viewing S7.94-120-17. Click any other SKU to view its full details.
| Product SKU | Pilot Diameter | Cutter Diameter | Inclusive Angle | Thread | Radius Between Pilot & Flute | Price | Stock | Order |
|---|---|---|---|---|---|---|---|---|
| S2.38-90-10 | 3/32 | 10 | 90 | M6X1 | 0.010 - 0.015 | £59.25 | 2-3 days | |
| S3.17-090-10 | 1/8 | 10 | 90 | M6X1 | 0.015 - 0.020 | £59.25 | 2-3 days | |
| S3.96-90-10 | 5/32 | 10 | 90 | M6X1 | 0.020 - 0.025 | £59.25 | 2-3 days | |
| S4.76-90-10 | 3/16 | 10 | 90 | M6X1 | 0.020 - 0.025 | £59.25 | 2-3 days | |
| S4.76-90-14 | 3/16 | 14 | 90 | M8X1 | 0.025 - 0.030 | £63.99 | 2-3 days | |
| S6.35-90-14 | 1/4 | 14 | 90 | M8X1 | 0.025 - 0.030 | £63.99 | 2-3 days | |
| S7.94-90-17 | 5/16 | 17 | 90 | M8X1 | 0.035 - 0.040 | £102.70 | 2-3 days | |
| S9.52-90-21 | 3/8 | 21 | 90 | M8X1 | 0.035 - 0.040 | £107.44 | 2-3 days | |
| S2.38-100-10 | 3/32 | 10 | 100 | M6X1 | 0.010 - 0.015 | £37.92 | 2-3 days | |
| S3.17-100-10 | 1/8 | 10 | 100 | M6X1 | 0.015 - 0.020 | £37.92 | 2-3 days | |
| S3.96-100-10 | 5/32 | 10 | 100 | M6X1 | 0.020 - 0.025 | £37.92 | 2-3 days | |
| S4.76-100-10 | 3/16 | 10 | 100 | M6X1 | 0.020 - 0.025 | £37.92 | 2-3 days | |
| S4.76-100-14 | 3/16 | 14 | 100 | M8X1 | 0.025 - 0.030 | £45.82 | 2-3 days | |
| S6.35-100-14 | 1/4 | 14 | 100 | M8X1 | 0.025 - 0.030 | £45.82 | 2-3 days | |
| S7.94-100-17 | 5/16 | 17 | 100 | M8X1 | 0.035 - 0.040 | £65.57 | 2-3 days | |
| S9.52-100-21 | 3/8 | 21 | 100 | M8X1 | 0.035 - 0.040 | £69.52 | 2-3 days | |
| S2.38-120-10 | 3/32 | 10 | 120 | M6X1 | 0.010 - 0.015 | £60.04 | 2-3 days | |
| S3.17-120-10 | 1/8 | 10 | 120 | M6X1 | 0.015 - 0.020 | £60.04 | 2-3 days | |
| S3.96-120-10 | 5/32 | 10 | 120 | M6X1 | 0.020 - 0.025 | £60.04 | 2-3 days | |
| S4.76-120-10 | 3/16 | 10 | 120 | M6X1 | 0.020 - 0.025 | £60.04 | 2-3 days | |
| S4.76-120-14 | 3/16 | 14 | 120 | M8X1 | 0.025 - 0.030 | £63.20 | 2-3 days | |
| S6.35-120-14 | 1/4 | 14 | 120 | M8X1 | 0.025 - 0.030 | £63.20 | 2-3 days | |
| S7.94-120-17 Viewing | 5/16 | 17 | 120 | M8X1 | 0.035 - 0.040 | £102.70 | 2-3 days | |
| S9.52-120-21 | 3/8 | 21 | 120 | M8X1 | 0.035 - 0.040 | £107.44 | 2-3 days |
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