Accupro 38855904 Ball End Mill 5/16 in 4 Flute Solid Carbide

Product Description

The ACCUPRO 38855904 is a single-end ball end mill designed for precision milling operations in ferrous and non-ferrous materials. Built from solid carbide, it delivers the rigidity and wear resistance required for high-speed, high-feed toolpaths. The cutting end measures 5/16 inches in diameter with a length of cut of 0.2910 inches and a neck length of 0.2500 inches. An AlTiCrN coating provides oxidation resistance and extended tool life at elevated cutting temperatures. This tool is installed and operated by machinists and CNC programmers in job shop and production environments where tight tolerances and surface finish are critical.

The 38855904 is suited for 3-axis and multi-axis CNC milling centers performing profiling, slotting, and finishing passes. Its four-flute geometry supports higher feed rates compared to two-flute designs, making it effective in medium to hard materials including alloy steels, stainless steels, and hardened workpieces. The variable index spacing reduces harmonic chatter during aggressive cuts. With a 5/16 inches shank diameter and 2-1/2 inches overall length, it fits standard collet and end mill holder tooling common in vertical and horizontal machining centers.

Key Features

• Solid carbide construction for rigidity and wear resistance in demanding materials
• AlTiCrN coating extends tool life and performance at high cutting temperatures
• 4-flute design supports higher feed rates and improved surface finish
• Variable index flute spacing reduces chatter and vibration during cutting
• Single-end configuration with 0.2910 inches length of cut and 0.2500 inches neck length
• 5/16 inches shank diameter fits standard collet and end mill holder systems

Compatibility

Designed as a standard single-end ball end mill for use in CNC vertical and horizontal machining centers equipped with collet chucks or end mill holders accepting a 5/16 inches shank diameter.

Installation Notes

Installation is performed by a qualified machinist or CNC operator. Ensure the spindle is fully stopped and the machine is in an e-stop or lockout state before changing tooling. Seat the shank fully into the collet or end mill holder and torque the retention hardware per the toolholder manufacturer specifications. Verify tool runout with a dial indicator before beginning production cuts to confirm proper seating and avoid premature tool wear or workpiece damage.