Keo 917-000-025 Countersink 1/4 in Hss 3 Flute Right Hand

Product Description

The KEO 917-000-025 is a single-end, straight-shank countersink designed for producing clean, accurately angled seat profiles in metal and similar materials. Built from high-speed steel, it delivers reliable cutting performance across a range of shop and field applications. The 100-degree included angle - corresponding to a 50-degree centerline angle - suits fastener seating requirements where a wide, flat countersink geometry is specified. With a 1/4-inch head diameter and a matching 1/4-inch straight-cylindrical shank, this tool fits standard drill chucks and collet holders without adapters. Three flutes provide balanced cutting action and adequate chip clearance for the head diameter. Right-hand cut orientation is compatible with standard CW-rotation machine spindles.

This countersink is suited for light-duty countersinking operations in machine shops, maintenance environments, and assembly applications. The 1/4-inch head diameter makes it appropriate for smaller fastener clearances - typically for screws in the No. 8 through No. 10 range depending on material and fastener standard. It can be run in a drill press, hand drill, or CNC machining center with a suitable collet or chuck setup. No pilot is included, so operator technique or a guide block is recommended when hole-to-hole position tolerance is critical.

Key Features

• 100-degree included angle (50-degree centerline angle) for wide-seat fastener countersinking
• High-speed steel construction for durability across metal and composite substrates
• 3-flute design provides balanced cutting and adequate chip clearance
• 1/4-inch straight-cylindrical shank fits standard drill chucks and collet holders
• Right-hand cut - compatible with standard clockwise-rotation spindles
• Single-end, no-pilot design for versatile use across varying hole sizes

Compatibility

Designed for use in drill presses, hand drills, and CNC machining centers equipped with a chuck or collet accepting a 1/4-inch straight shank. No specific OEM model compatibility is stated by the manufacturer for this tool.

Installation Notes

This tool is installed and operated by machinists, tool-and-die technicians, and maintenance professionals. Secure the shank fully in the chuck or collet before operation, and ensure the workpiece is firmly fixtured to prevent rotation or movement during cutting. Because no pilot is included, use a center punch mark, drill guide, or existing pilot hole to locate the countersink accurately. Always reduce spindle speed relative to standard twist-drill speeds when countersinking to avoid chatter and premature tool wear.