Osg 5402300 Square End Mill 3/4 in 4 Flute Cobalt

Product Description

The OSG 5402300 is a cobalt square end mill designed for milling operations in ferrous and hard materials where high-speed steel would wear prematurely. Built to Series 540 standards, it features a 0.750-inch cutting diameter, a 1.625-inch length of cut, and a 4-flute spiral geometry with a 30-degree helix angle. The 0.625-inch shank diameter provides solid tool holding in standard end mill holders or collet chucks. Material grade M42 cobalt construction offers increased heat and wear resistance compared to standard M2 HSS, making this end mill well suited for production environments where tool life matters. Installation and operation are handled by machinists and CNC setup technicians.

This end mill is intended for peripheral and slot milling applications on machining centers, knee mills, and manual or CNC vertical mills. The right-hand cut, right-hand spiral flute configuration is the standard orientation for the majority of milling setups. The regular-length classification and 3.750-inch overall length make it appropriate for general-purpose work where extended reach is not required. It is not center-cutting, so it should not be used for direct plunge entry into solid material without a pre-drilled clearance hole or a ramping entry path.

Key Features

• M42 cobalt construction provides elevated heat resistance and longer tool life compared to standard HSS in tough materials
• 30-degree helix angle promotes efficient chip evacuation and smooth cutting action
• 4-flute design balances material removal rate with chip clearance for general milling work
• Right-hand cut and right-hand spiral flute for standard spindle-direction compatibility
• Uncoated finish allows for straightforward resharpening when needed
• Non-center-cutting geometry — requires ramping or pre-drilled entry for plunge operations

Compatibility

Designed as a direct-fit replacement or standard tooling selection for setups requiring a 0.625-inch shank, 0.750-inch diameter square end mill in Series 540 regular-length configuration. Compatible with any end mill holder, collet chuck, or Weldon-style holder accommodating a 5/8-inch shank diameter.

Installation Notes

Installation is performed by a machinist or CNC technician. Ensure the machine spindle is fully stopped and the control is in a safe state before changing tooling. Verify holder bore and runout tolerances before seating the shank, and torque set screws or collet nuts to the tool holder manufacturer specifications. Confirm entry path programming accounts for the non-center-cutting geometry before running the first pass.