Keo 919-000-377 Countersink 5/16 in 90 Degree 6 Flute Hss

Product Description

The KEO 919-000-377 is a single-end, straight-shank countersink designed for producing clean, accurately angled seat profiles in metal and similar materials. It features a 5/16-inch head diameter, a 90-degree included angle (45-degree centerline angle), and 6 flutes for smooth chip evacuation and consistent finish quality. The tool is manufactured from high-speed steel for durability under standard machining conditions. The 1/4-inch straight-cylindrical shank seats securely in standard drill chucks and collet holders. This countersink does not include a pilot and is intended for use without one, making it straightforward to position by eye or with a guide fixture.

This countersink is suited for light to medium fabrication work in machine shops, manufacturing lines, and maintenance environments. It handles typical countersinking tasks for flat-head fastener seating in steel, aluminum, and similar workpiece materials. The right-hand cutting direction is standard for conventional drilling setups. The 7/8-inch shank length provides adequate engagement in most tool holders used on drill presses, CNC machines, or hand drills.

Key Features

• 5/16-inch head diameter for countersinking small to medium fastener holes
• 90-degree included angle, 45-degree centerline angle for standard flat-head fastener seating
• 6-flute geometry promotes smooth cutting and reduces chatter
• High-speed steel construction for general-purpose machining durability
• 1/4-inch straight-cylindrical shank fits standard drill chucks and collet holders
• Right-hand cut, no pilot, single end for straightforward application

Compatibility

Designed as a general-purpose countersink for use in standard drill chucks and collet holders accepting a 1/4-inch straight-cylindrical shank, compatible with drill presses, CNC machining centers, and hand drills configured for right-hand cutting tools.

Installation Notes

Installation and use of this countersink should be performed by a qualified machinist or trained operator. Secure the shank fully in the tool holder before operation and verify that the machine spindle is at a complete stop before making any adjustments. Select an appropriate spindle speed for the workpiece material to avoid overheating the high-speed steel cutting edges. Inspect the cutting edges for wear or damage before each use and replace the tool if chipping or dullness is observed.