Iscar 5621258 Corner Radius End Mill 3/8 in 4 Flute Carbide

Product Description

The ISCAR 5621258 is a solid carbide corner radius end mill designed for precision milling in demanding metalworking applications. It carries a 3/8-inch diameter with a 0.02-inch corner radius and a 3/4-inch length of cut, making it well-suited for both roughing and finishing passes. The 4-flute, right-hand helical geometry paired with a PVD-applied AlTiN coating provides thermal resistance and hardness retention at elevated cutting temperatures. With a 3-inch overall length and a straight cylindrical shank held to h6 tolerance, this tool seats securely in standard toolholders. It is installed and operated by machinists and CNC tool-and-die professionals working with high-strength alloys.

The 5621258 is engineered for use on steel, stainless steel, cast iron, superalloys, titanium, and hard materials. Its medium helix and normal pitch geometry handles both roughing and finishing in a single tool, reducing changeovers on CNC machining centers and manual mills. The 3/8-inch shank diameter matches the cutter diameter for direct clamping in collet chucks or end mill holders without an adapter. The ECI-E-4R series designation identifies this as a submicron carbide grade tool within the ISCAR solid mill product line, appropriate for high-speed and hard-material applications.

Key Features

• 0.02-inch corner radius reduces stress concentration at part corners and extends tool life in high-feed passes
• AlTiN PVD coating provides oxidation resistance and hardness at elevated cutting temperatures
• Submicron carbide substrate supports use in hard materials and superalloys including titanium
• 4-flute right-hand helical geometry supports both roughing and finishing without tool change
• Straight cylindrical shank with h6 tolerance ensures precise, repeatable runout in collet and end mill holders
• Center-cutting capable, allowing plunge entry without a pre-drilled pilot hole

Compatibility

Designed for use with standard toolholders accepting a 3/8-inch straight cylindrical shank. Compatible with CNC machining centers and manual milling machines set up for right-hand cutting. Primary workpiece materials include steel, stainless steel, cast iron, superalloys, titanium, and hard materials (ISO material codes P, M, K, S, H).

Installation Notes

Installation should be performed by qualified machinists following shop safety protocols. Secure the shank to the full recommended engagement depth in the toolholder and torque the retention mechanism per toolholder manufacturer specifications before powering the spindle. Inspect the collet or end mill holder for wear and runout before seating the tool, as excess runout accelerates corner radius wear on carbide tooling. Never exceed the cutting parameters specified in the ISCAR ECI-E-4R series application guide for the workpiece material being machined.