Osg 5204400 Square End Mill 1-1/4 in 2 Flute Cobalt

Product Description

The OSG 5204400 is a cobalt square end mill designed for milling operations requiring a durable, heat-resistant cutting tool. Built from M42 cobalt high-speed steel, this end mill delivers reliable performance in tough ferrous and non-ferrous materials. It features a 1.25-inch cutting diameter, a 1.625-inch length of cut, and a 30-degree helix angle with spiral fluting for efficient chip evacuation. The two-flute configuration provides generous chip clearance, making it well-suited for slotting and peripheral milling. Licensed machinists and tool-and-die professionals are the primary installers and users of this tool.

The OSG 5204400 is part of the Series 520 regular-length end mill line. It is configured as a single-end, center-cutting tool with right-hand cut and right-hand flute direction. This combination makes it appropriate for conventional plunge cutting as well as standard milling passes. The 0.875-inch shank diameter is sized for R8 and other common toolholding systems found in vertical knee mills, CNC machining centers, and manual mills used in job shops, maintenance facilities, and production environments.

Key Features

• M42 cobalt construction for heat and wear resistance in demanding cuts
• Center-cutting design allows direct plunge entry without pre-drilling
• 30-degree helix spiral flute promotes smooth chip evacuation and surface finish
• Right-hand cut and right-hand flute — standard configuration for most milling setups
• Two-flute geometry provides maximum chip clearance for slotting applications
• Uncoated finish suitable for use with cutting fluids on a wide range of workpiece materials

Compatibility

Designed as an OEM-style replacement and standard tooling option for milling machines accepting a 0.875-inch shank diameter end mill holder or collet system.

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 into the holder and torque set screws or collet nuts per the toolholder manufacturer specifications. Inspect the cutting edges for chips or damage before each use and replace the tool if wear exceeds acceptable limits for the application.