Robbjack ST-434-12-A Corner Chamfer End Mill 3/8 in 4 Flute

Product Description

The ROBBJACK ST-434-12-A is a solid carbide corner chamfer end mill designed for precision edge preparation and chamfering on ferrous and exotic workpiece materials. This single-end tool features a 3/8-inch cutting diameter, four helical flutes at a 30-degree helix angle, and a 45-degree chamfer angle, making it well-suited for both roughing and finishing passes. The AlTiN (aluminum titanium nitride) PVD coating provides elevated heat resistance and wear protection, extending tool life in demanding cutting environments. Licensed machinists and CNC programmers working in job shops, aerospace, and heavy manufacturing will find this tool appropriate for side milling and edge chamfer applications.

The ST-434-12-A is intended for use on steel, stainless steel, cast iron, superalloys, and titanium workpieces, corresponding to material codes P, M, K, and S. With a 7/8-inch length of cut, 3/8-inch straight cylindrical shank, and a 2.5-inch overall length, this tool fits standard ER and set-screw toolholders commonly used on vertical machining centers and CNC mills. It performs side milling operations and is suited for both production and prototype environments where consistent chamfer geometry is required.

Key Features

• 45-degree chamfer angle with 0.0050-inch chamfer length for controlled edge break geometry
• AlTiN PVD coating for improved heat resistance and extended tool life on hard and abrasive materials
• Four right-hand helical flutes at 30-degree helix angle for efficient chip evacuation
• Solid carbide construction for rigidity and dimensional stability under high cutting loads
• Straight cylindrical shank with tight diameter tolerance (-0.0001 to -0.0002 inches) for secure toolholder engagement
• Rated for roughing and finishing material removal on steel, stainless steel, cast iron, superalloys, and titanium

Compatibility

Designed for use on steel, stainless steel, cast iron, superalloys, and titanium workpieces (material codes P, M, K, S). Fits standard 3/8-inch ER collet chucks and set-screw end mill holders used on CNC vertical and horizontal machining centers.

Installation Notes

Installation and operation should be performed by a qualified CNC machinist or tooling technician. Ensure the machine spindle is fully stopped and the tool is securely seated in the toolholder before beginning any setup. Verify runout with a dial indicator after clamping, as chamfer end mills are sensitive to runout-induced geometry errors. Follow the machine tool manufacturer and cutting tool manufacturer recommendations for speeds, feeds, and depth of cut for the specific workpiece material.