Osg 5426600 Square End Mill 21/64 in 4 Flute Cobalt

Product Description

The OSG 5426600 is a double-end cobalt square end mill designed for milling operations in ferrous and hard materials where heat resistance and edge retention are critical. Built from M42 cobalt high-speed steel, this tool features a 21/64 inch (0.3281 inch) cutting diameter, a 3/4 inch length of cut, and a 30-degree helix angle. Four right-hand spiral flutes deliver efficient chip evacuation during peripheral and slot milling. The bright, uncoated finish is standard for this Series 542 tool. It is installed and operated by machinists and tool-and-die professionals in manual and CNC milling environments.

This end mill is suited for ferrous metal machining applications where cobalt tooling outperforms standard high-speed steel under elevated cutting temperatures. The double-end configuration provides two usable cutting ends, extending tool life per unit. With a 3/8 inch shank diameter and a regular-length body at 3-1/2 inches overall, it fits standard collet chucks and end mill holders used in vertical mills, knee mills, and CNC machining centers. This tool is not center-cutting, so it is not intended for direct plunge operations.

Key Features

• M42 cobalt HSS construction for elevated heat and wear resistance
• Double-end design — two cutting ends per tool for extended usable life
• 30-degree right-hand helix with four right-hand spiral flutes for efficient chip flow
• 21/64 inch cutting diameter with 3/4 inch length of cut
• Bright/uncoated finish — compatible with cutting fluids and oils without coating interference
• Not center-cutting — designed for peripheral and slot milling, not plunge entry

Compatibility

Designed as an OEM-style replacement or standard tooling selection for 3/8 inch collet chucks and end mill holders used in vertical milling machines and CNC machining centers requiring a 21/64 inch square end mill profile.

Installation Notes

Installation is performed by qualified machinists following standard toolholding procedures. Ensure the milling machine spindle is fully powered down and locked out before inserting or removing the tool from the holder. Secure the shank firmly in a properly sized collet or end mill holder to the holder manufacturer's specified torque range — do not use torque values not sourced from the holder documentation. Confirm cutting direction is set to right-hand rotation before engaging the workpiece.