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Robert Charles Piloted Microstop Countersink - 3 Flute - Integral Pilot - Threaded Shank - 17mm Cutter Dia - 5/16 Pilot Diameter - 100°
| Pilot Diameter | 5/16 |
| Cutter Diameter | 17 |
| Inclusive Angle | 100 |
| Thread | M8X1 |
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Description
The Robert Charles Piloted Microstop Countersink is a precision 3-flute countersink with an integral pilot, designed for repeatable, high-accuracy countersinking. Its 17 mm cutter diameter and 100° countersink angle deliver clean, uniform chamfers on aerospace, automotive, and precision-engineering parts. The integrated pilot aligns with drilled holes for true positioning, while the threaded shank locks into microstop cages for secure depth control and quick, repeatable setups. The pilot diameter is held to −0.0005" to −0.0015" to maintain tight tolerances across jobs.
- Precision 3-Flute Cutting Design: enables efficient material removal with minimal deflection, producing consistent countersinks and smooth edge quality across production runs.
- Integral Pilot for Accurate Hole Alignment: built-in pilot guides the cutter precisely to the hole, reducing misalignment and rework in assemblies.
- Threaded Shank with Microstop Cage Compatibility: secure fit and reliable depth control, supporting quick setups and repeatable countersink depths.
Engineered for reliability in demanding workflows, this countersink helps you improve first-pass yield, shorten setup times, and achieve consistent, professional results in every hole. Its robust construction and tight pilot tolerances translate to fewer tool changes, less scrap, and clearer, cleaner finishes across aerospace, automotive, and precision-engineering applications.
Part Numbers
- Protool Part Number
- S7.94-100-17
- 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 S7.94-100-17. 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 Viewing | 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 | 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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