Chicago-latrobe 56774 Countersink 3/4 in 90 Degree Hss

Product Description

The CHICAGO-LATROBE 56774 is a single-flute high speed steel countersink designed for chamfering, countersinking, and deburring operations in metal fabrication and machining applications. It features a 3/4 inch head diameter, a 90-degree included angle, and a straight cylindrical shank for secure chuck mounting. The oxide finish provides a base level of lubricity and corrosion resistance. With a 1-27/32 inch overall length and single-end configuration, this tool delivers consistent geometry in production and maintenance environments. Licensed machinists, tool and die techs, and maintenance mechanics are the primary users.

This countersink is suited for creating clean, chamfered seat profiles in alloy steel, cast iron, and tool steel workpieces. It handles standard countersinking for flathead fasteners, light deburring of drilled holes, and chamfering operations where a 90-degree included angle is the specified geometry. The right-hand cut direction is compatible with conventional drill press, milling machine, and hand-held drill setups. Its compact single-end straight shank design fits most standard drill chucks and collet holders without adapters.

Key Features

• 3/4 inch head diameter with a 90-degree included angle and 45-degree centerline angle
• Single flute geometry provides clearance and reduces chatter in harder workpiece materials
• High speed steel construction handles alloy steel, cast iron, and tool steel
• Oxide finish reduces friction and provides mild corrosion protection
• Straight cylindrical shank fits standard drill chucks and collet systems
• Single-end, no-pilot design for flexibility across varied hole sizes

Compatibility

Designed for use in alloy steel, cast iron, and tool steel applications requiring a 90-degree countersink profile. Compatible with standard drill press spindles, milling machine chucks, and handheld drills accepting a straight cylindrical shank.

Installation Notes

Install and tighten the shank securely in the chuck or collet before operation. Power down and lock out the machine before changing tooling per standard OSHA lockout/tagout procedures. Use appropriate cutting fluid or lubricant when countersinking harder alloy steels or cast iron to extend tool life and maintain finish quality. Inspect the cutting edge for wear before each use, as a dull single-flute tool can cause chatter and irregular seat geometry.