Please log in here to access all benefits, including multibuy discounts and faster checkouts.


Robert Charles Plain Shank Counterbore M35-HSS-E 5% Cobalt - 5/16 Cap Screw Size - 0.343 Pilot Size
| Cap Screw Size | 5/16 |
| Pilot Size | 0.343 |
| Cutting Diameter | 0.507 |
| Shank Size | 3/8 |
| Overall Length | 4.5 |
Learn more about Klarna
Engineered for precision counterboring, the Robert Charles Plain Shank Counterbore delivers durable, reliable performance for machinists, engineers, and automotive shops that require clean, consistent holes. Crafted from M35 HSS-E with 5% cobalt, it excels under demanding cutting conditions to maintain sharpness and accuracy over time.
- Material: M35 HSS-E with 5% cobalt for enhanced heat resistance, wear life, and cutting performance.
- Shank type: Plain shank designed for straightforward fitment in standard tool holders and stable machining.
- Pilot size: 0.343" pilot diameter to align the hole accurately during counterboring.
- Cap screw compatibility: 5/16" cap screw size for secure workholding and repeatable setups.
- Counterbore geometry: Optimized geometry for clean, precise counterbores with consistent chip control.
- Applications: Ideal for precision engineering, automotive fabrication, and general workshop use where durable, repeatable results are essential.
This counterbore is built to deliver dependable performance across repetitive tasks and challenging materials. The combination of cobalt-enhanced HSS-E and a stable plain shank means you can rely on accurate bore depths, smooth chip formation, and a clean bottom for flush screw seating. It’s a practical, high-value choice for professionals who value consistency and efficiency in every project.
| Cap Screw Size | 5/16 |
| Pilot Size | 0.343 |
| Cutting Diameter | 0.507 |
| Shank Size | 3/8 |
| Overall Length | 4.5 |
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 Plain Shank Counterbores M35-HSS-E 5% Cobalt
View full collection →You are viewing 5770-5/16-1/32 OVER. Click any other SKU to view its full details.
| Product SKU | Cap Screw Size | Pilot Size | Cutting Diameter | Shank Size | Overall Length | Price | Stock | Order |
|---|---|---|---|---|---|---|---|---|
| 5770-4-CLOSE FIT | #4 | 0.112 | 0.186 | 5/32 | 3 | £33.97 | 2-3 days | |
| 5770-4-1/64 OVER | #4 | 0.127 | 0.202 | 5/32 | 3 | £33.97 | 2-3 days | |
| 5770-4-1/32 OVER | #4 | 0.143 | 0.217 | 5/32 | 3 | £33.97 | 2-3 days | |
| 5770-5-CLOSE FIT | #5 | 0.125 | 0.205 | 3/16 | 3 | £34.76 | 2-3 days | |
| 5770-5-1/64 OVER | #5 | 0.140 | 0.221 | 3/16 | 3 | £34.76 | 2-3 days | |
| 5770-5-1/32 OVER | #5 | 0.156 | 0.237 | 3/16 | 3 | £34.76 | 2-3 days | |
| 5770-6-CLOSE FIT | #6 | 0.138 | 0.228 | 7/32 | 3 | £34.76 | 2-3 days | |
| 5770-6-1/64 OVER | #6 | 0.153 | 0.244 | 7/32 | 3 | £34.76 | 2-3 days | |
| 5770-6-1/32 OVER | #6 | 0.169 | 0.260 | 7/32 | 3 | £34.76 | 2-3 days | |
| 5770-8-CLOSE FIT | #8 | 0.164 | 0.272 | 1/4 | 3 | £35.55 | 2-3 days | |
| 5770-8-1/64 OVER | #8 | 0.179 | 0.288 | 1/4 | 3 | £35.55 | 2-3 days | |
| 5770-8-1/32 OVER | #8 | 0.195 | 0.304 | 1/4 | 3 | £35.55 | 2-3 days | |
| 570-10-CLOSE FIT | #10 | 0.19 | 0.314 | 9/32 | 4.5 | £37.92 | 2-3 days | |
| 5770-10-1/64 OVER | #10 | 0.205 | 0.33 | 9/32 | 4.5 | £37.92 | 2-3 days | |
| 5770-10-1/32 OVER | #10 | 0.221 | 0.346 | 9/32 | 4.5 | £37.92 | 2-3 days | |
| 5770-1/4-CLOSE FIT | 1/4 | 0.25 | 0.382 | 5/16 | 4.5 | £41.87 | 2-3 days | |
| 5770-1/4-1/64 OVER | 1/4 | 0.265 | 0.398 | 5/16 | 4.5 | £41.87 | 2-3 days | |
| 5770-1/4-1/32 OVER | 1/4 | 0.281 | 0.414 | 5/16 | 4.5 | £41.87 | 2-3 days | |
| 5770-5/16-CLOSE FIT | 5/16 | 0.312 | 0.475 | 3/8 | 4.5 | £47.40 | 2-3 days | |
| 5770-5/16-1/64 OVER | 5/16 | 0.328 | 0.491 | 3/8 | 4.5 | £47.40 | 2-3 days | |
| 5770-5/16-1/32 OVER Viewing | 5/16 | 0.343 | 0.507 | 3/8 | 4.5 | £47.40 | 2-3 days | |
| 5770-3/8-CLOSE FIT | 3/8 | 0.375 | 0.572 | 1/2 | 5 | £63.99 | 2-3 days | |
| 5770-3/8-1/64 OVER | 3/8 | 0.39 | 0.588 | 1/2 | 5 | £63.99 | 2-3 days | |
| 5770-3/8-1/32 OVER | 3/8 | 0.406 | 0.604 | 1/2 | 5 | £63.99 | 2-3 days | |
| 5770-7/16-CLOSE FIT | 7/16 | 0.437 | 0.663 | 1/2 | 5 | £85.32 | 2-3 days | |
| 5770-7/16-1/64 OVER | 7/16 | 0.452 | 0.679 | 1/2 | 5 | £85.32 | 2-3 days | |
| 5770-7/16-1/32 OVER | 7/16 | 0.468 | 0.695 | 1/2 | 5 | £85.32 | 2-3 days | |
| 5770-1/2-CLOSE FIT | 1/2 | 0.5 | 0.757 | 1/2 | 6 | £109.02 | 2-3 days | |
| 5770-1/2-1/64 OVER | 1/2 | 0.515 | 0.773 | 1/2 | 6 | £109.02 | 2-3 days | |
| 5770-1/2-1/32 OVER | 1/2 | 0.531 | 0.789 | 1/2 | 6 | £109.02 | 2-3 days | |
| 5770-5/8-1/64 OVER | 5/8 | 0.641 | 0.961 | 5/8 | 6 | £142.20 | 2-3 days | |
| 5770-5/8-CLOSE FIT | 5/8 | 0.625 | 0.945 | 5/8 | 6 | £142.20 | 2-3 days | |
| 5770-5/8-1/32 OVER | 5/8 | 0.656 | 0.977 | 5/8 | 6 | £142.20 | 2-3 days | |
| 5770-3/4-CLOSE FIT | 3/4 | 0.766 | 1.187 | 3/4 | 7 | £211.72 | 2-3 days | |
| 5770-3/4-1/32 OVER | 3/4 | 0.781 | 1.203 | 3/4 | 7 | £211.72 | 2-3 days | |
| 5770-7/8-CLOSE FIT | 7/8 | 0.891 | 1.375 | 7/8 | 7 | £255.96 | 2-3 days | |
| 5770-7/8-1/32 OVER | 7/8 | 0.906 | 1.391 | 7/8 | 7 | £255.96 | 2-3 days |
No products match your filters.