Robbjack STR-404-12-T Square End Mill 3/8 in 4 Flute Carbide

Product Description

The ROBBJACK STR-404-12-T is a solid carbide square end mill designed for precision milling in metal, composite, and engineered material applications. It features a 3/8-inch cutting diameter, a 7/8-inch length of cut (LOC), and a 3/8-inch shank diameter with an overall length of 2-1/2 inches. The four-flute, single-end geometry with a 30-degree helix angle and fine pitch delivers smooth chip evacuation and stable cutting performance. A titanium nitride (TiN) finish improves surface hardness and wear resistance, extending tool life in general-purpose machining operations. This tool is centercutting, allowing plunge entry directly into workpiece material.

This end mill is suited for slotting, profiling, and peripheral milling operations in CNC machining centers and manual mills. Its regular-length configuration and right-hand cut with right-hand flute direction make it a standard fit for general shop use across job shops, production floors, and tool rooms. The 3/8-inch diameter is a common size for finish passes and detail work in ferrous and non-ferrous materials. Machinists and CNC operators working with steel, aluminum, and similar materials will find the STR-404 series geometry appropriate for everyday milling tasks.

Key Features

• 3/8-inch cutting diameter with 7/8-inch length of cut for controlled depth engagement
• Solid carbide construction for rigidity and wear resistance versus high-speed steel alternatives
• TiN coating increases surface hardness and reduces friction at the cutting edge
• 30-degree helix angle with fine pitch promotes smooth chip flow and reduced chatter
• Centercutting design allows direct plunge milling without pre-drilled entry
• Right-hand cut, right-hand flute - standard orientation compatible with conventional CNC spindle rotation

Compatibility

Designed as an OEM-style replacement or standard tooling option for 3/8-inch collet or end mill holders used in CNC machining centers and manual milling machines requiring a 3/8-inch shank, four-flute square end mill.

Installation Notes

Installation is performed by qualified machinists or CNC operators. Secure the shank fully into the collet or tool holder to the recommended engagement depth before tightening - never leave insufficient shank engagement. Confirm spindle direction is set to right-hand rotation before initiating a cut. Inspect the cutting edges for chips or wear before each use, as carbide tooling can fracture under interrupted cuts if the edge is compromised.