Osg HP421-3125 Square End Mill 5/16 in 2 Flute Carbide

Product Description

The OSG HP421-3125 is a solid carbide square end mill designed for precision milling in demanding metal-cutting applications. Built from micrograin carbide and finished with a TiAlN coating, this tool delivers high wear resistance and thermal stability at elevated cutting speeds. It measures 0.3125 inches in diameter with a 0.8125-inch length of cut, a 0.3125-inch shank diameter, and a 2.5-inch overall length. The 35-degree helix spiral flute geometry promotes efficient chip evacuation while reducing cutting forces. Licensed machinists and tool-and-die professionals will find this end mill well suited for profiling, slotting, and peripheral milling in ferrous and hardened materials.

This end mill is a single-end, center-cutting tool with a right-hand cut and right-hand flute configuration, making it compatible with standard CNC machining centers and manual knee mills. The 2-flute design provides adequate chip clearance in tighter pockets and slots where chip packing is a concern. It belongs to OSG Series HP421, a line optimized for high-performance applications in steel, stainless steel, and similar materials where tool life and surface finish consistency are priorities. Typical installation scenarios include production shops, tool rooms, and maintenance machining environments.

Key Features

• Micrograin solid carbide construction for superior hardness and edge retention
• TiAlN finish provides high-temperature oxidation resistance for dry or minimum-quantity-lubrication cutting
• 35-degree helix angle for improved chip evacuation and reduced cutting pressure
• Center-cutting design enables direct plunge entry without a pre-drilled hole
• Right-hand cut and right-hand spiral flute for use in standard spindle direction
• 2-flute configuration suited for slotting and profiling where chip clearance is critical

Compatibility

Designed as an OEM-style replacement or direct-fit tooling option for standard 5/16-inch collets, end mill holders, and hydraulic chucks used in CNC machining centers and conventional milling machines.

Installation Notes

Installation should be performed by qualified machinists following shop safety procedures. Ensure the spindle is fully stopped and the machine is locked out before loading or unloading the tool. Seat the shank fully in the holder to the minimum insertion depth recommended by the holder manufacturer to prevent pullout under cutting loads. Inspect the cutting edges and TiAlN coating before each use — chipped or worn edges should not be run, as degraded tooling increases the risk of workpiece damage and unexpected tool failure.