Accupro 311186 Ball End Mill 1/4 in 4 Flute Solid Carbide

Product Description

The ACCUPRO 311186 is a solid carbide ball end mill designed for high-performance milling in ferrous and hardened materials. With a 0.2500 inch mill diameter, a 38-degree helix angle, and an AlTiCrN coating, this tool delivers heat resistance and extended tool life in demanding cutting applications. The four-flute, single-end configuration with a variable index design reduces harmonic vibration, improving surface finish and dimensional accuracy. Machined from micrograin carbide stock, the 311186 holds tight diameter tolerances of plus 0.000 and minus 0.001 inches. It is suited for CNC machining centers and manual mills operated by machinists and tooling specialists working in job shop, production, and tool-and-die environments.

This end mill is built for profiling, contouring, and finishing passes in ferrous metals, stainless steel, and hardened alloys where a ball nose profile is required. The straight-cylindrical shank seats cleanly in ER collet chucks and end mill holders. With a 3/4 inch length of cut and a 2.5 inch overall length, the 311186 is suited for standard-reach applications where rigidity is a priority. The HS series designation indicates a high-speed application profile optimized for modern machining parameters at elevated feed rates.

Key Features

• AlTiCrN coating for elevated temperature resistance and extended tool life in ferrous and hardened materials
• 38-degree right-hand helix for efficient chip evacuation and reduced cutting force
• Variable index flute spacing minimizes chatter and improves surface finish
• Micrograin solid carbide substrate for superior hardness and edge retention
• Tight mill diameter tolerance of plus 0.000 and minus 0.001 inches for precise fitment
• Single-end, right-hand cutting direction with no chipbreaker for clean ball-nose profiling

Compatibility

Designed as a standard-reach solid carbide ball end mill for use in ER collet chucks, end mill holders, and shrink-fit tooling systems accepting a 1/4 inch straight-cylindrical shank. Part of the ACCUPRO HS series.

Installation Notes

Installation should be performed by a qualified machinist following shop safety procedures. Ensure the spindle is fully stopped and the machine is powered down before changing tooling. Seat the shank to the recommended gauge line depth in the holder and torque the collet nut or set screw per the toolholder specification. Confirm runout with a dial indicator before beginning a production cut to verify proper seating and avoid premature edge wear.