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Cleveland 91711 counterbore 5/16 inch 6.000 inch long .438 inch diameter bright finish

Cleveland

Cleveland 91711 Counterbore 5/16 in 6.000 in L .438 in dia Bright

SKU CH-RJBT-APA15

A 5/16 in high-speed steel counterbore with built-in pilot, 6.000 in overall length and .438 in diameter, bright finish

  • High-speed steel construction resists wear
  • Built-in pilot ensures accurate hole alignment
  • 5/16 in fractional size fits standard applications
  • 000 in overall length provides extended reach
  • Bright finish reduces friction during cutting

Cleveland 91711 Counterbore

The Cleveland 91711 is a high-speed steel counterbore with a built-in pilot designed for fractional inch work. It suits machinists and maintenance technicians who need to create flat-bottomed holes for socket-head fasteners in metal components. The bright finish indicates an uncoated surface suitable for general-purpose cutting applications. This tool is supplied new and ready for immediate workshop use.

Cutting interface limits

The counterbore operates with a 5/16 inch cutting diameter and a .438 inch pilot diameter to guide the tool accurately. Its 6.000 inch overall length provides reach for deeper holes while maintaining rigidity during the cut. High-speed steel construction offers reliable wear resistance in mild steels and non-ferrous metals but will dull faster than carbide in abrasive alloys. No coating means lubrication is essential to prevent built-up edge and overheating.

Setup checks before ordering

Verify that your drill press or milling machine accepts the shank style implied by the tool's design and can run at appropriate speeds for high-speed steel. Confirm the .438 inch pilot matches the clearance hole size in your workpiece to ensure proper alignment. Ensure you have cutting fluid available, as the bright finish requires lubrication for performance and tool life. Buyers needing coated tooling or carbide substrate for high-volume production should look elsewhere.

How it compares

Measured against everything we stock in Bits, Hole Saws & Accessory Kits, at today’s prices. Recalculated every night.

Price $123.99
Pricier than about 87% of the 5,493 comparable items (median $27.99).

Specifications

Product
Brand nameCLEVELAND

Questions about this item

Should I choose the 5/16 in counterbore with the .438 in pilot diameter or a different size?

The 5/16 in counterbore features a .438 in pilot diameter designed for that specific screw size; select it when your hardware matches those dimensions.

How does the 6.000 in overall length affect reach in a drill press or hand drill?

The 6.000 in length provides extended reach for deeper holes while maintaining rigidity during counterboring operations in a drill press or hand drill.

What does the standard fractional inch shank mean for compatibility with my chuck?

The standard fractional inch shank fits common 3-jaw drill chucks and quick-change adapters without requiring metric collets or special holders.

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