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Robert Charles Plain Shank Counterbore M35-HSS-E 5% Cobalt - 7/8 Cap Screw Size - 0.891 Pilot Size

Robert Charles Plain Shank Counterbore M35-HSS-E 5% Cobalt - 7/8 Cap Screw Size - 0.891 Pilot Size

SKU:5770-7/8-CLOSE FIT

The Robert Charles Plain Shank Counterbore is a high-performance tool engineered for precise, repeatable counterboring in metalworking. Designed for machinists, engineers, and workshop profession... Read more ↓
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Cap Screw Size7/8
Pilot Size0.891
Cutting Diameter1.375
Shank Size7/8
Overall Length7
£255.96
Prices shown ex. VAT
2–3 days estimated lead time — subject to availability
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01732 887334
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The Robert Charles Plain Shank Counterbore is a high-performance tool engineered for precise, repeatable counterboring in metalworking. Designed for machinists, engineers, and workshop professionals, it pairs durability with straightforward integration into standard tool holders.

  • Material: M35-HSS-E with 5% cobalt for improved heat resistance, wear life, and cutting performance at higher speeds.
  • Shank Type: Plain shank for easy clamping in conventional tool holders, delivering stable and reliable machining.
  • Counterbore Size: 7/8 inch counterbore diameter compatible with standard cap screws and flush seating.
  • Pilot Size: 0.891 inch pilot provides precise start and accurate hole centering for clean counterbores.
  • Geometry: Optimized flute design and relief to promote efficient chip evacuation and minimal chatter.
  • Applications: Ideal for precision engineering, automotive assembly, and general workshop tasks requiring durable, consistent counterboring results.

This counterbore delivers consistent, repeatable results across workpieces, helping you achieve flush-cap screw seating with minimal rework. The cobalt-enhanced HSS composition maintains cutting efficiency during extended machining cycles, while the plain shank simplifies setup and reduces tool-change time. Built for reliability in demanding environments, it’s a practical choice for shops that value accuracy, durability, and steady performance.

Cap Screw Size 7/8
Pilot Size 0.891
Cutting Diameter 1.375
Shank Size 7/8
Overall Length 7

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.

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Staff are very helpful and interested in providing a good service making us the customer feel valued.
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honest about stock and prices are competitive.
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Staff are very helpful and polite.Goods that were in stock were dispatched same day and back orders were quick in coming through .
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Buying experience
Phone requests are handled quickly and without any fuss. The website is easy to use and straightforward to order from. It’s especially helpful that it shows real‑time availability, so we don’t need to call to confirm whether parts will arrive.
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Full Range: Robert Charles Plain Shank Counterbores M35-HSS-E 5% Cobalt

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You are viewing 5770-7/8-CLOSE FIT. Click any other SKU to view its full details.

Product SKUCap Screw SizePilot SizeCutting DiameterShank SizeOverall LengthPriceStock Order
5770-4-CLOSE FIT #40.1120.1865/323£33.97 2-3 days
5770-4-1/64 OVER #40.1270.2025/323£33.97 2-3 days
5770-4-1/32 OVER #40.1430.2175/323£33.97 2-3 days
5770-5-CLOSE FIT #50.1250.2053/163£34.76 2-3 days
5770-5-1/64 OVER #50.1400.2213/163£34.76 2-3 days
5770-5-1/32 OVER #50.1560.2373/163£34.76 2-3 days
5770-6-CLOSE FIT #60.1380.2287/323£34.76 2-3 days
5770-6-1/64 OVER #60.1530.2447/323£34.76 2-3 days
5770-6-1/32 OVER #60.1690.2607/323£34.76 2-3 days
5770-8-CLOSE FIT #80.1640.2721/43£35.55 2-3 days
5770-8-1/64 OVER #80.1790.2881/43£35.55 2-3 days
5770-8-1/32 OVER #80.1950.3041/43£35.55 2-3 days
570-10-CLOSE FIT #100.190.3149/324.5£37.92 2-3 days
5770-10-1/64 OVER #100.2050.339/324.5£37.92 2-3 days
5770-10-1/32 OVER #100.2210.3469/324.5£37.92 2-3 days
5770-1/4-CLOSE FIT 1/40.250.3825/164.5£41.87 2-3 days
5770-1/4-1/64 OVER 1/40.2650.3985/164.5£41.87 2-3 days
5770-1/4-1/32 OVER 1/40.2810.4145/164.5£41.87 2-3 days
5770-5/16-CLOSE FIT 5/160.3120.4753/84.5£47.40 2-3 days
5770-5/16-1/64 OVER 5/160.3280.4913/84.5£47.40 2-3 days
5770-5/16-1/32 OVER 5/160.3430.5073/84.5£47.40 2-3 days
5770-3/8-CLOSE FIT 3/80.3750.5721/25£63.99 2-3 days
5770-3/8-1/64 OVER 3/80.390.5881/25£63.99 2-3 days
5770-3/8-1/32 OVER 3/80.4060.6041/25£63.99 2-3 days
5770-7/16-CLOSE FIT 7/160.4370.6631/25£85.32 2-3 days
5770-7/16-1/64 OVER 7/160.4520.6791/25£85.32 2-3 days
5770-7/16-1/32 OVER 7/160.4680.6951/25£85.32 2-3 days
5770-1/2-CLOSE FIT 1/20.50.7571/26£109.02 2-3 days
5770-1/2-1/64 OVER 1/20.5150.7731/26£109.02 2-3 days
5770-1/2-1/32 OVER 1/20.5310.7891/26£109.02 2-3 days
5770-5/8-1/64 OVER 5/80.6410.9615/86£142.20 2-3 days
5770-5/8-CLOSE FIT 5/80.6250.9455/86£142.20 2-3 days
5770-5/8-1/32 OVER 5/80.6560.9775/86£142.20 2-3 days
5770-3/4-CLOSE FIT 3/40.7661.1873/47£211.72 2-3 days
5770-3/4-1/32 OVER 3/40.7811.2033/47£211.72 2-3 days
5770-7/8-CLOSE FIT Viewing7/80.8911.3757/87£255.96 2-3 days
5770-7/8-1/32 OVER 7/80.9061.3917/87£255.96 2-3 days

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