Osg 86300509 Square End Mill 0.25 in 3 Flute Solid Carbide

Product Description

The OSG 86300509 is a solid carbide square end mill designed for precision milling operations in metalworking and machining environments. With a 0.25 inch cutting diameter, a 1 inch length of cut, and a 2.5 inch overall length, this tool is built for high-accuracy profiling, slotting, and contouring work. The 40-degree helix angle promotes efficient chip evacuation and reduces cutting forces, while the diamond-like carbon (DLC) finish extends tool life and lowers friction. Three flutes provide a balance between chip clearance and cutting edge strength. The 0.25 inch shank fits standard collets and end mill holders common in machining centers and manual mills.

This end mill is suited for general-purpose and finish milling applications in ferrous and non-ferrous materials. Its centercutting geometry allows plunge entry, making it versatile for pocketing operations. The right-hand cut and right-hand flute configuration is standard for conventional CNC machining center spindles. It is typically used by machinists and toolroom operators working on parts requiring tight dimensional tolerances and clean edge finish.

Key Features

• 0.25 inch cutting diameter with 1 inch length of cut for controlled depth engagement
• 40-degree helix angle improves chip flow and reduces heat buildup at the cutting edge
• DLC finish reduces friction and extends tool life in demanding materials
• Centercutting design enables plunge milling and ramp entry
• Solid carbide construction provides rigidity and wear resistance over high-speed tool steel alternatives
• Right-hand cut, right-hand flute — compatible with standard CNC spindle rotation

Compatibility

Designed as a direct-fit replacement for 0.25 inch shank end mill applications in standard ER collets, end mill holders, and side-lock holders used on CNC machining centers and manual knee mills.

Installation Notes

Installation should be performed by a qualified machinist following shop safety procedures. Ensure the spindle is fully stopped and machine power is off before changing tooling. Seat the shank to the recommended minimum engagement depth in the collet or holder — typically no less than the shank diameter multiplied by three — and torque the retention system per the holder manufacturer specification. Inspect the collet and bore for runout before engaging the workpiece.