Robbjack ST-646-16-A Corner Radius End Mill 1/2 in 6 Flute

Product Description

The ROBBJACK ST-646-16-A is a single-end, corner radius end mill engineered for high-performance milling in demanding materials. Built from solid carbide and coated with AlTiN via a PVD process, it delivers extended tool life in dry or semi-dry cutting conditions. The 1/2-inch diameter cutter features 6 flutes with a variable helix and variable index geometry, reducing harmonic chatter and improving surface finish. A corner radius range of 0.0060 to 0.0090 inches protects the cutting edge from chipping at depth. This tool is installed and run by machinists and CNC operators in job shop, production, and toolroom environments.

The ST-646-16-A is suited for milling steel, stainless steel, cast iron, superalloys, and titanium. With a 1-inch length of cut (0.875 inches decimal), a 1/2-inch straight-cylindrical shank, and a 3-inch overall length, it fits standard toolholders used on vertical and horizontal machining centers. The close pitch flute configuration and right-hand cutting direction make it a practical choice for side milling, slotting, and finishing passes in tough alloys.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard and abrasive workpiece materials
• AlTiN PVD coating extends tool life and supports elevated cutting temperatures in ferrous and exotic alloys
• Variable helix and variable index design reduces vibration and chatter during aggressive cuts
• Corner radius of 0.0060 to 0.0090 inches reduces edge chipping and improves corner strength
• Centercutting capability allows plunge entry without a pre-drilled pilot hole
• 6-flute, close-pitch configuration supports higher feed rates in finishing and semi-finishing operations

Compatibility

Designed for use with standard straight-bore toolholders accepting a 1/2-inch cylindrical shank. Primary workpiece materials include steel, stainless steel, cast iron, superalloys, and titanium (material codes P, M, K, S). Part of the ROBBJACK ST-646 series.

Installation Notes

Install in a compatible toolholder and torque set screws or collet nuts to the toolholder manufacturer's specification before use. Confirm shank is fully seated and free of chips or burrs prior to clamping. This tool does not support coolant-through delivery; use external coolant or appropriate cutting fluid directed at the cutting zone. Follow your machine tool manufacturer's recommended runout tolerance and RPM limits for solid carbide end mills of this diameter.