Robbjack NR-303-12 Square End Mill 3/8 in 3 Flute Carbide

Product Description

The ROBBJACK NR-303-12 is a solid carbide square end mill from the NR-303 series, designed for precision milling in metalworking and machining applications. With a 3/8-inch cutting diameter, 7/8-inch length of cut, and 3 spiral flutes, it delivers clean, accurate cuts in a compact regular-length profile. The right-hand cut and right-hand flute geometry, combined with a 30-degree helix angle, promote efficient chip evacuation and stable tool engagement. This end mill is center-cutting, allowing direct plunge entry into workpiece material. It is installed and used by machinists and CNC operators in production and job-shop environments.

The NR-303-12 is suited for milling operations in ferrous and non-ferrous materials where a solid carbide uncoated tool in the C2 material grade is appropriate. The straight cylindrical shank at 3/8 inch fits standard collet chucks and end mill holders. Its regular-length configuration makes it a practical choice for slotting, profiling, and peripheral milling at moderate depths. No chipbreaker, extended reach, variable helix, or variable index features are present, keeping the geometry straightforward for general-purpose milling work.

Key Features

• Solid carbide construction, C2 material grade, for rigidity and wear resistance
• 3 spiral flutes with 30-degree helix angle for efficient chip flow
• Center-cutting design allows direct plunge milling without pre-drilling
• Right-hand cut and right-hand flute geometry for standard spindle rotation
• Uncoated finish; no chipbreaker, extended reach, variable helix, or variable index
• Mill diameter tolerance of +0.001/-0.000 inches for consistent fit and finish

Compatibility

The NR-303-12 uses a 3/8-inch straight cylindrical shank and is compatible with standard collet chucks, ER collets, and end mill holders sized for 3/8-inch shank tooling on CNC machining centers and manual milling machines.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator. Ensure the machine spindle is fully stopped and locked out before inserting or removing the end mill from the tool holder. Seat the shank fully into the collet or holder to the manufacturer-recommended engagement depth and torque the retention mechanism per the tool holder specifications. Inspect the cutting edges for chips or damage before each use.