Osg 4558908 Corner Chamfer End Mill 0.25in 4 Flute Cobalt

Product Description

The OSG 4558908 is a corner chamfer end mill designed for precise edge-breaking and chamfering operations on metal workpieces. Built from cobalt high-speed steel and finished with a TiCN coating, it offers improved wear resistance and heat tolerance over standard HSS tooling. The 4-flute geometry and 30-degree helix angle promote efficient chip evacuation and a smooth finish in both ferrous and non-ferrous materials. With a 0.25-inch cutting diameter and 0.25-inch length of cut, this end mill is sized for detailed work in tight features. It is centercutting, allowing plunge entry without a pre-drilled hole.

This end mill is suited for use in vertical machining centers, CNC knee mills, and manual milling machines where chamfering, edge-breaking, and light profiling are required. The 3/8-inch shank diameter fits standard ER collet chucks and side-lock holders common in production and job-shop environments. Fine pitch geometry makes it appropriate for harder materials and finishing passes where surface quality matters.

Key Features

• Cobalt construction for elevated heat and wear resistance compared to standard HSS
• TiCN coating reduces friction and extends tool life in abrasive materials
• 4-flute, right-hand cutting and flute direction for rigidity and smooth finish
• 30-degree helix angle promotes chip flow and reduces cutting forces
• Centercutting design allows direct plunge entry
• Fine pitch geometry suited for harder workpiece materials and finishing passes

Compatibility

Designed as a direct-fit replacement or standard tooling addition for CNC and manual milling setups accepting a 3/8-inch shank end mill with ER collet or side-lock retention.

Installation Notes

Installation and tool changes must be performed with the machine powered down and the spindle fully stopped. Use a calibrated torque wrench when tightening collet nuts to avoid over-clamping the shank. Verify runout with a dial indicator before cutting to maximize tool life and surface finish quality. This tool should be installed by a qualified machinist or CNC operator familiar with proper toolholding practices.