Kennametal 3899139 Corner Radius End Mill 7/16in 5 Flute

Product Description

The KENNAMETAL 3899139 is a solid carbide corner radius end mill engineered for demanding material removal in steel, stainless steel, cast iron, superalloys, titanium, and hard materials. It carries a 7/16 inch (0.4375 inch) cutting diameter and a 1 inch length of cut, with an overall length of 2.5 inches and a matching 7/16 inch straight-cylindrical shank. The five-flute geometry supports both roughing and finishing operations, while the AlTiN (aluminum titanium nitride) PVD coating delivers heat and wear resistance at elevated cutting speeds. The high helix style promotes efficient chip evacuation and reduces cutting forces across a broad range of workpiece materials. This tool is installed by machinists and CNC tooling technicians in production and job-shop environments.

The 3899139 belongs to the KENNAMETAL UCDE series and is suited for vertical and horizontal machining center applications where corner radius geometry is required to reduce stress concentrations at shoulder features. Its right-hand cutting direction and right-hand flute spiral make it compatible with standard CNC spindle configurations. Single-end construction and normal pitch designate it for precision setups where tool runout and repeatability are critical. Typical applications include contouring, profiling, and full-width slotting in steel alloys, hardened steels, and nickel-based superalloys. The submicron carbide grade provides the rigidity and edge retention needed for consistent results in hard materials.

Key Features

• Solid carbide submicron grade construction for rigidity and edge retention in hard workpiece materials
• AlTiN PVD coating resists heat and oxidation during high-speed cutting of steel, cast iron, and superalloys
• Five-flute design balances chip room with surface finish capability across roughing and finishing passes
• High helix style promotes efficient chip evacuation and lowers cutting forces
• Corner radius end type reduces stress at shoulders and extends tool life compared to sharp-corner geometry
• Right-hand cut and right-hand spiral flute direction compatible with standard CNC machining center spindles

Compatibility

Designed for use with ER single angle standard collets and TT-SS tooling systems. Straight-cylindrical shank diameter of 0.4375 inches fits standard 7/16 inch collet bores. Intended for CNC machining center applications cutting steel, stainless steel, cast iron, superalloys, titanium, and hard materials.

Installation Notes

Installation is performed by qualified machining technicians or CNC setup personnel. Ensure the machine spindle is fully stopped and the tool changer is in a safe state before loading or removing the end mill. Secure the shank in a matched ER collet or compatible toolholder, torquing the collet nut according to the toolholder manufacturer specifications. Confirm runout at the cutting diameter before commencing cuts, as excessive runout accelerates edge wear and reduces corner radius accuracy.