Keo 917-000-059 Countersink 3/8 in 90 Deg 3 Flute Hss

Product Description

The KEO 917-000-059 is a single-end, three-flute countersink designed for creating clean, chamfered entry holes in metal and similar workpiece materials. Manufactured from high-speed steel, it features a 3/8 inch head diameter and a 90-degree included angle, which corresponds to a 45-degree centerline angle. The straight-cylindrical shank measures 1/4 inch in diameter and 7/8 inch in length for secure chuck retention. Right-hand cutting action makes it compatible with standard drill press and hand-drill setups. Machinists, toolroom technicians, and maintenance trades use this style of countersink for deburring, bolt-seat preparation, and screw-head recessing.

This countersink is suited for general-purpose countersinking operations in light manufacturing, maintenance, and fabrication environments. It is appropriate for use in drill presses, hand drills, and CNC machining centers where a 1/4 inch straight shank toolholder or collet is available. The 90-degree included angle is the standard for flat-head machine screw and bolt applications. No pilot is included, so the operator positions the tool at the pre-drilled hole center before engaging the cut.

Key Features

• 3/8 inch head diameter for moderate countersink diameters in standard fastener applications
• 90-degree included angle matches flat-head screw and bolt seat geometry
• Three flutes provide a balance of cutting speed and surface finish quality
• High-speed steel construction offers durability across a range of ferrous and non-ferrous materials
• 1/4 inch straight-cylindrical shank fits standard drill chucks and collets without an adapter
• Right-hand cut for use with conventional clockwise-rotation tooling

Compatibility

Designed as a general-purpose countersink for use in any machine or hand-held tool accepting a 1/4 inch straight-cylindrical shank, including drill presses, hand drills, and compatible CNC spindles.

Installation Notes

This tool is installed by a machinist or maintenance technician into a drill chuck or collet rated for a 1/4 inch straight shank. Always power down or lock out the machine before changing tooling. Pre-drill the pilot hole to the fastener body diameter before countersinking; the tool does not include a pilot. Run at appropriate spindle speeds for the workpiece material to avoid work hardening or tool damage.