Eagle Cutting Tool CS-3750-100-6-I Hss Countersink 6 Flute

Product Description

The EAGLE CUTTING TOOL CS-3750-100-6-I is a high-speed steel (HSS) countersink designed for producing clean, chamfered seat holes in metal, wood, and composite materials. The tool features a 3/8-inch cutting diameter, a 100-degree included angle, and six flutes for smooth chip evacuation and a chatter-resistant cut. The 1/4-inch straight shank fits standard drill chucks and quick-change holders without adapters. Machinists, fabricators, and metalworking tradespeople rely on this style of countersink for deburring and seating flat-head fasteners to flush or below-flush depth.

This countersink is suited for production and maintenance applications where a consistent 100-degree chamfer is required. The 100-degree angle is a common specification for metric and certain aerospace-style flat-head fasteners, distinguishing it from the more common 82-degree and 90-degree countersinks used in standard inch-fastener work. It is appropriate for use in drill presses, CNC machining centers, and hand-held electric drills when a drill press stop or depth collar is used to control depth.

Key Features

• High-speed steel construction provides durability across ferrous and non-ferrous materials
• 100-degree included angle seats metric and specialty flat-head fasteners correctly
• Six-flute design reduces chatter and produces a smoother finish than single- or three-flute countersinks
• 3/8-inch cutting diameter sized for common small to medium fastener heads
• 1/4-inch straight shank compatible with standard drill chucks and quick-change systems

Compatibility

Designed as a standard straight-shank countersink compatible with any drill press, milling machine, or hand drill accepting a 1/4-inch shank toolholder or chuck.

Installation Notes

This tool is installed by a machinist or fabricator into a 1/4-inch drill chuck or quick-change holder. Ensure the machine spindle is fully stopped and power is disconnected or the chuck key is removed before inserting or removing the tool. Use a depth stop collar or CNC depth parameter to prevent over-countersinking, which can weaken the workpiece around the fastener seat. Do not exceed the recommended RPM range for HSS tooling in the material being machined.

Technical Specifications

• Cutting Diameter: 3/8 inches
• Shank Diameter: 1/4 inches
• Included Angle: 100 degrees
• Number of Flutes: 6
• Material: High-Speed Steel (HSS)
• Weight: 0.05 pounds

Standard Information

• Brand: EAGLE CUTTING TOOL
• Manufacturer Part Number: CS-3750-100-6-I