Value Collection GH8861486 Solid Pilot Counterbore 3MT

Product Description

The VALUE COLLECTION GH8861486 is a solid pilot counterbore designed for enlarging and finishing bolt-hole seats in metal workpieces to precise, flat-bottomed recesses. Built from high speed steel, this tool delivers the hardness and heat resistance required for production and maintenance machining on steel, cast iron, and similar ferrous materials. The 1-3/16 inch counterbore diameter pairs with a 13/16 inch standard pilot to maintain concentricity with the existing hole. Three flutes provide a balance of cutting efficiency and chip clearance. The Morse Taper 3 shank mounts directly into compatible taper-socket spindles on drill presses and milling machines.

This counterbore is suited for general machining and maintenance applications where a 3/4 inch fastener must seat flush or below the workpiece surface. Typical use cases include fabrication shops, toolrooms, and field maintenance operations that require a clean, flat-bottomed recess for socket head cap screws or other 3/4 inch fasteners. Forward cutting direction is standard for conventional right-hand spindle rotation. The 3MT shank makes it compatible with machines fitted with a Number 3 Morse Taper socket, a common configuration on floor-standing drill presses and knee mills.

Key Features

• 1-3/16 inch counterbore diameter sized for 3/4 inch fastener clearance
• 13/16 inch standard pilot maintains concentricity with pilot hole
• High speed steel construction for durability on ferrous materials
• 3-flute geometry balances cutting speed and chip evacuation
• Morse Taper 3 (3MT) shank for direct mounting in compatible spindles
• Forward cutting direction for standard right-hand spindle rotation

Compatibility

Designed for use in drill presses, milling machines, and similar equipment fitted with a Number 3 Morse Taper spindle socket. Sized to produce a flat-bottomed recess for 3/4 inch fasteners.

Installation Notes

Installation and operation should be performed by a qualified machinist or toolroom technician. Power down and lock out the machine spindle before mounting or removing the tool from the taper socket. Clean both the taper shank and the spindle socket before seating to ensure full contact and concentricity. Always verify spindle speed is appropriate for the workpiece material and tool diameter before engaging the cut.