Osg 5200400 Square End Mill 5/16 in 2 Flute Cobalt

Product Description

The OSG 5200400 is a two-flute cobalt square end mill designed for milling operations in ferrous and non-ferrous materials. Built from M42 cobalt high-speed steel, it delivers heat resistance and edge retention that standard HSS tooling cannot match. The cutter measures 0.3125 inches in diameter with a 9/16-inch length of cut and a 3/8-inch shank diameter, making it a compact, rigid tool suited to slotting, profiling, and light pocketing. The 30-degree helix angle promotes smooth chip evacuation and reduces cutting forces. It is an uncoated, centercutting design, meaning it can plunge directly into the workpiece. Machinists, tool-and-die makers, and CNC operators are the primary users of this tool.

The 5200400 is intended for use in manual knee mills, CNC machining centers, and drill-press setups where a 3/8-inch collet or end mill holder is available. Its regular-length geometry suits general-purpose work in steel, stainless steel, cast iron, and high-temperature alloys where cobalt tooling is preferred over carbide for interrupted cuts or setups prone to vibration. The 2-5/16-inch overall length keeps overhang minimal, which supports better surface finish and tool life. This end mill ships individually and is well-suited to job shop, maintenance, and production environments that require a reliable general-purpose cobalt cutter in the 5/16-inch diameter range.

Key Features

• M42 cobalt high-speed steel construction for heat resistance and edge retention
• Centercutting geometry allows direct plunge entry into the workpiece
• 30-degree helix angle promotes efficient chip evacuation and reduced cutting force
• Right-hand cut, right-hand spiral flute configuration for standard CNC and manual setups
• Uncoated finish suitable for re-sharpening and use with cutting fluids
• Regular-length body minimizes overhang and supports rigid, accurate cuts

Compatibility

Designed as a direct-fit replacement or general-purpose cobalt square end mill for any machine tool accepting a 3/8-inch shank, including collet chucks, end mill holders, and Weldon-flat holders. Part of the OSG Series 520 product line.

Installation Notes

This tool is installed and changed by machinists or CNC operators following standard tooling procedures. Ensure the machine spindle is fully stopped and the control is in an e-stop or tool-change state before inserting or removing the end mill. Use a properly sized collet or end mill holder torqued to the machine manufacturer specification. Inspect the shank for nicks or runout before seating, and verify tool reach and clearance in the program or setup before running a full cut.