Cleveland C91750 Solid Pilot Hss Counterbore Set 9 Pc

Product Description

The CLEVELAND C91750 is a 9-piece solid pilot counterbore set made from high-speed steel (HSS) with a bright, uncoated finish. Designed for fast material removal and consistent bore geometry, this set covers a wide range of wire gauge sizes from 32 to 6 wire. Each counterbore features a straight shank, standard pilot, and 3-flute cutting geometry for smooth chip evacuation and accurate seating of fastener heads. The set ships in a wood storage case that organizes all pieces and protects cutting edges between uses. At 3.89 pounds, the assembled set is robust enough for production and maintenance shop environments alike.

This counterbore set is suited for metalworking applications requiring precise counterbored holes for socket head cap screws, shoulder bolts, and similar fasteners. It is used in general machining, toolroom, and maintenance-repair-operations (MRO) contexts. The forward cutting direction and 3-flute design allow use in drill presses, milling machines, and hand-operated setups. The 32 to 6 wire gauge range makes it a practical all-in-one solution when multiple counterbore sizes are needed at a single workstation.

Key Features

• High-speed steel construction for durability across steel, aluminum, and similar workpiece materials
• Bright uncoated finish for general-purpose use without added coating costs
• 3-flute geometry promotes chip clearance and smooth cutting action
• Standard pilot design ensures concentricity between pilot hole and counterbore
• Straight shank compatible with standard drill chucks and collets
• Wood storage case included to protect and organize all 9 pieces

Compatibility

Compatible with 32 to 6 wire gauge pilot hole sizes. Designed as a standard solid-pilot counterbore set for use in drill presses, milling machines, and similar machine tool setups where straight-shank tooling is accepted.

Installation Notes

Counterbores of this type are installed and operated by machinists or maintenance technicians familiar with rotating cutting tools. Always secure the workpiece firmly before starting the spindle, and confirm the pilot diameter matches the pre-drilled hole before engaging the cutter. Use cutting fluid appropriate to the workpiece material to extend tool life and improve surface finish. Inspect pilot and flute condition before each use and replace any piece showing chipping or wear.