Robbjack FM-204-10-120 Corner Radius End Mill 5/16in

Product Description

The ROBBJACK FM-204-10-120 is a solid carbide corner radius end mill designed for precision milling of non-ferrous metals. It features a 5/16-inch (0.3125-inch) mill diameter with a 0.12-inch corner radius, delivering controlled edge geometry that reduces chipping and improves surface finish on aluminum, copper, brass, and similar materials. The 2-flute configuration promotes efficient chip evacuation in gummy materials. With a high-helix spiral flute design and bright/uncoated finish, this tool is optimized for high-speed, light-to-moderate material removal in production and job-shop environments. A straight cylindrical shank makes it compatible with standard end mill holders and collet chucks.

This end mill suits CNC machining centers and manual mills handling non-ferrous metal workpieces in both production and prototype applications. The extended-reach geometry, with a reach length of 1.313 inches and a neck diameter of 0.2969 inches, allows access to deeper features and pocketing operations where a standard-length tool would contact the workpiece shoulder. It is a single-end, centercutting tool, meaning it can plunge directly into material as well as perform conventional and climb peripheral cuts. The FM-204 series is positioned as a long-length option for applications requiring clearance depth.

Key Features

• 0.12-inch corner radius reduces stress concentration at the cutting edge and improves tool life on non-ferrous materials
• 2-flute design maximizes chip gullet size for efficient evacuation in aluminum and other gummy metals
• Extended-reach geometry with 1.313-inch reach length and reduced neck diameter for deep-pocket access
• Centercutting capability allows direct plunge entry without pre-drilling
• Right-hand cut, right-hand flute spiral with high-helix style for aggressive chip removal
• Bright/uncoated solid carbide construction suited for non-ferrous and abrasive-free workpiece materials

Compatibility

Designed for use with standard toolholders accepting a 5/16-inch straight cylindrical shank. Primary workpiece material is non-ferrous metal (material code N), including aluminum, brass, copper, and similar alloys.

Installation Notes

Installation should be performed by a qualified machinist following shop safety protocols. Ensure the machine spindle is fully powered down and locked out before loading or changing tooling. Secure the shank to the minimum recommended engagement depth in the toolholder collet or end mill holder to maintain runout control - maximum TIR for this tool is 0.0005 inches. Verify holder condition and collet cleanliness before clamping, as contamination or worn collets will increase runout and reduce tool life.