Robbjack STR-301-10-A Square End Mill 5/16 in 3 Flute Carbide

Product Description

The ROBBJACK STR-301-10-A is a solid carbide square end mill designed for precision milling in demanding machining environments. Part of the STR-301 series, this stub-length, single-end tool features a 5/16 inch cutting diameter, a 1/2 inch length of cut, and a 5/16 inch shank diameter with an overall length of 2.5 inches. The three-flute, fine-pitch geometry with a 30-degree helix angle promotes efficient chip evacuation and smooth cutting action. An AlTiN coating adds heat and wear resistance, extending tool life in abrasive or high-temperature cutting conditions. Right-hand cut and right-hand flute orientation are standard.

This end mill is suited for slot milling, peripheral milling, and profile work in ferrous and non-ferrous materials where a stub-length tool provides added rigidity. The centercutting capability allows plunge entry, giving machinists flexibility in toolpaths without requiring a pre-drilled entry point. The compact stub-length form factor reduces deflection, making it a practical choice for short, tight-tolerance cuts on CNC machining centers and manual mills alike. It is typically selected by machinists and tool-and-die professionals working in job shop, aerospace, and general metalworking applications.

Key Features

• Solid carbide construction for rigidity and extended tool life
• AlTiN coating for heat resistance and reduced wear in high-temperature cuts
• Three-flute, fine-pitch geometry with 30-degree helix for smooth chip flow
• Centercutting design allows direct plunge entry
• Stub length reduces deflection and improves rigidity in tight setups
• Right-hand cut and right-hand flute orientation

Compatibility

Designed as an OEM-style replacement and standard tooling option for 5/16 inch collets and tool holders on CNC machining centers and manual milling machines requiring a stub-length square end mill with a 5/16 inch shank.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician. Ensure the machine spindle is fully stopped and locked out before changing tooling. Seat the shank fully in the collet or tool holder and torque the retention mechanism to the machine manufacturer's specification. Inspect the cutting edges for chips or coating damage before each use.