Osg 5400205 Square End Mill 3/16 in 4 Flute Cobalt Tin

Product Description

The OSG 5400205 is a cobalt square end mill designed for milling ferrous metals, stainless steels, and other tough materials in CNC machining and manual milling applications. Built from M42 cobalt high-speed steel with a titanium nitride (TiN) coating, this tool offers elevated heat resistance and extended tool life compared to standard HSS end mills. It features a 3/16 inch cutting diameter, a 1/2 inch length of cut, and a 30-degree right-hand spiral helix. Installed by machinists and tool-and-die professionals, it fits standard milling machines and machining centers using a 3/8 inch shank collet or holder.

This end mill is suited for general-purpose profiling, slotting, and peripheral milling in job shop and production environments. The 4-flute configuration provides a good balance of chip clearance and surface finish quality, making it effective for finishing passes on ferrous alloys and medium-hardness steels. It is not center-cutting, so it requires a pre-drilled entry point or ramping approach for plunge operations. At 2-3/8 inches overall length with a regular-length classification, it fits close-clearance setups without excessive overhang.

Key Features

• M42 cobalt HSS construction for increased heat and wear resistance over standard HSS
• TiN coating extends tool life and reduces friction on ferrous workpieces
• 30-degree right-hand spiral flute promotes efficient chip evacuation
• 4-flute design supports improved surface finish in finishing and semi-finishing cuts
• 3/8 inch shank diameter for broad collet and end mill holder compatibility
• Not center-cutting — requires pre-drilled entry or ramp entry for plunge cuts

Compatibility

Designed as an OEM-style replacement or direct-fit tooling option for milling machines and machining centers accepting a 3/8 inch shank end mill. Part of OSG Series 540.

Installation Notes

Installation is performed by qualified machinists following shop-standard tool-change procedures. Ensure the spindle is fully stopped and machine power is locked out before changing tooling. Seat the shank fully in the collet or end mill holder and torque the drawbar or nut to the machine manufacturer's specification. Verify runout with a dial indicator before beginning a cut, particularly on finishing operations.