Robbjack NR-204-08 Square End Mill 1/4 in 2 Flute Carbide

Product Description

The ROBBJACK NR-204-08 is a 2-flute solid carbide square end mill designed for precision milling in metalworking and machining applications. Built to Series NR-204 specifications, it features a 0.25 inch cutting diameter, a 0.75 inch length of cut, and a 2.5 inch overall length. The straight cylindrical shank measures 0.25 inch in diameter, providing secure tool holding in standard collet chucks. Manufactured from C2-grade solid carbide, this end mill offers the rigidity and wear resistance required for ferrous and non-ferrous cutting. Right-hand cut and right-hand spiral flute geometry with a 30-degree helix angle promotes efficient chip evacuation and smooth cutting action.

This end mill is suited for slotting, profiling, and peripheral milling operations on CNC machining centers and manual knee mills. Its centercutting capability allows direct plunge entry into the workpiece, reducing the need for pre-drilled pilot holes. The uncoated finish and regular length classification make it a standard workhorse tool for general-purpose milling of aluminum, brass, mild steel, and similar materials in job shop and production environments. Machinists and CNC operators working in tool-and-die, aerospace component, or general fabrication settings are the primary users.

Key Features

• Solid carbide C2-grade construction for rigidity and wear resistance
• Centercutting geometry allows direct plunge milling without a pilot hole
• 30-degree right-hand spiral flute promotes efficient chip removal
• Straight cylindrical shank compatible with standard ER and DA collet systems
• Uncoated finish suitable for general-purpose ferrous and non-ferrous applications
• Regular length classification for stable, low-deflection cuts

Compatibility

Designed as a general-purpose replacement or direct-use solid carbide square end mill for standard 1/4 inch collet or end mill holder setups on CNC machining centers and manual milling machines.

Installation Notes

Installation is performed by qualified machinists or CNC setup technicians. Ensure the machine spindle is fully stopped and the control is in E-stop or lockout/tagout state before changing tooling. Seat the shank fully into the collet or tool holder and torque the retention nut to the tool holder manufacturer specification. Verify runout with a dial indicator before initiating a cutting program, as excess runout on a small-diameter end mill accelerates wear and increases breakage risk.