Osg 20552503 Corner Radius End Mill 1/4 in 5 Flute Carbide

Product Description

The OSG 20552503 is a single-end corner radius end mill ground from ultra-fine micrograin solid carbide and coated with OSG EXO TiAlN via PVD process. It carries a 1/4 inch cutting diameter, a 0.06 inch corner radius, and five variable-helix flutes configured for right-hand cut and right-hand flute direction. The variable helix and variable index geometry reduce harmonic vibration during aggressive cuts, making this tool well-suited for both roughing and finishing passes in a single setup. Overall length is 2.5 inches with a 5/8 inch length of cut.

This end mill is engineered for demanding workpiece materials including stainless steel, superalloys, and titanium, as well as hardened stock. The 1/4 inch straight cylindrical shank mounts directly into a standard toolholder. It is a regular-length tool designed for CNC machining centers and manual mills where tight corner radii and edge integrity are required. The centercutting design allows plunge entry. No coolant-through feature is present, so flood or mist coolant delivery from the spindle side is the standard approach for these materials.

Key Features

• Ultra-fine micrograin solid carbide substrate for edge strength and wear resistance in hard materials
• EXO TiAlN PVD coating provides high heat resistance during dry and semi-dry cutting of stainless and superalloys
• Variable helix and variable index geometry suppress chatter and extend tool life in difficult-to-machine materials
• 0.06 inch corner radius protects the cutting edge and improves surface finish at part corners
• Five-flute configuration increases feed rate capability versus standard four-flute tooling at equivalent chip load
• Centercutting design permits direct plunge milling without a pre-drilled pilot

Compatibility

Designed for use with standard straight-bore toolholders accepting a 1/4 inch cylindrical shank. Mill diameter tolerance is 0.0000 to -0.0020 inches; shank diameter tolerance is h6. Intended for use on CNC machining centers cutting stainless steel, superalloys, titanium, and hard materials per OSG Series 2055 application guidelines.

Installation Notes

Installation and tool changes must be performed with the machine spindle fully stopped and the control in an estop or tool-change state. Confirm toolholder bore and collet size match the 1/4 inch h6 shank before mounting. Verify runout at the toolholder after tightening, as excessive runout accelerates edge wear on fine-grain carbide. Consult the machine tool builder and OSG cutting data recommendations for speeds, feeds, and depth of cut before first use in hardened or superalloy workpieces.