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Robert Charles Plain Shank Counterbore M35-HSS-E 5% Cobalt - 1/4 Cap Screw Size - 0.281 Pilot Size
| Cap Screw Size | 1/4 |
| Pilot Size | 0.281 |
| Cutting Diameter | 0.414 |
| Shank Size | 5/16 |
| Overall Length | 4.5 |
Learn more about Klarna
The Robert Charles Plain Shank Counterbore is designed for engineers and machinists who demand clean, precise counterboring with reliable durability. Crafted from M35 HSS-E with 5% cobalt, it delivers exceptional heat resistance and wear life for consistent performance in challenging materials.
- Material: M35 HSS-E with 5% cobalt for enhanced heat resistance, wear life, and cutting performance.
- Shank Type: Plain shank for easy fitment in standard tool holders, enabling quick changes and stable machining.
- Size & Pilot: 1/4 cap screw size with a 0.281" pilot for accurate hole depth and alignment.
- Counterbore Geometry: Optimized geometry and cutting edges to produce clean, flat-bottom counterbores with minimal chatter.
- Tolerance & Finish: Precision-ground to deliver consistent hole dimensions across multiple operations.
- Applications: Ideal for precision engineering, automotive manufacturing, and general workshop fabrication where durability matters.
This counterbore provides dependable performance in daily machining tasks, reducing rework and downtime. The cobalt-infused HSS optimizes heat management during deep countersinking, helping maintain edge life and cut quality even in tougher metals. The straightforward plain shank simplifies setup in common tool holders, supporting steady feeds and true hole depth for accurate fastener seating and fixture alignment.
| Cap Screw Size | 1/4 |
| Pilot Size | 0.281 |
| Cutting Diameter | 0.414 |
| Shank Size | 5/16 |
| 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 5770-1/4-1/32 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 Viewing | 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 | 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 |
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