Osg 5204100 Square End Mill 7/8 Inch 2 Flute Cobalt

Product Description

The OSG 5204100 is a cobalt square end mill designed for milling ferrous and harder workpiece materials in metalworking and machining applications. Built to Series 520 standards, it features a 7/8 inch cutting diameter, a 1-1/2 inch length of cut, and a 30-degree helix angle with spiral fluting. The 2-flute geometry supports efficient chip evacuation and is center-cutting capable, allowing plunge entry directly into a workpiece. Material grade M42 cobalt construction provides elevated heat and wear resistance compared to standard high-speed steel, making it well suited for demanding milling operations on steel, stainless, and similar alloys.

This end mill is intended for use in vertical machining centers, knee mills, and manual milling machines across job shops, tool rooms, and production environments. The right-hand cut and right-hand flute configuration are the standard orientation for conventional and climb milling on most CNC and manual setups. The regular-length body and 7/8 inch shank diameter fit directly into standard collet chucks, end mill holders, and shell mill adapters sized for 7/8 inch shanks.

Key Features

• Cobalt M42 material grade for superior heat resistance and edge retention over standard HSS
• Center-cutting design allows direct plunge milling without a pre-drilled entry point
• 30-degree helix angle with spiral flutes promotes smooth cutting action and chip flow
• 2-flute configuration provides clearance for chip evacuation in slotting and pocketing operations
• Right-hand cut and right-hand flute orientation matches standard machine spindle direction
• Uncoated finish suitable for use with cutting fluids on a wide range of metals

Compatibility

Designed as an OEM-style replacement or standard tooling selection for machines accepting 7/8 inch shank end mills in Series 520 regular-length configurations.

Installation Notes

Installation should be performed by a qualified machinist or tooling technician. Ensure the machine spindle is fully stopped and locked out before inserting or removing the end mill from the holder. Confirm the shank is fully seated in the collet or end mill holder to the recommended engagement depth before tightening. Follow the machine manufacturer and tooling manufacturer guidelines for speeds, feeds, and cutting fluid application based on workpiece material.