Accupro 12182859 Square End Mill 21/64 in 4 Flute Carbide

Product Description

The ACCUPRO 12182859 is a solid carbide square end mill designed for precision milling operations in metal, composite, and hard material applications. Built from micrograin carbide, it delivers consistent edge integrity at higher feed rates and speeds than HSS alternatives. The 21/64 inch (0.3281 inch) cutting diameter pairs with a 40-degree helix angle and spiral flute geometry to improve chip evacuation and reduce cutting forces. With a 5/8 inch length of cut and 2 inch overall length, this is a stub-length tool optimized for rigidity in tight-clearance setups. Installed by machinists and tool-and-die professionals on CNC mills and manual knee mills alike.

This end mill fits standard 3/8 inch ER or end mill collet holders and is well suited for slotting, profiling, and finishing passes on ferrous and non-ferrous workpieces. The centercutting design allows plunge entry without a pre-drilled hole, expanding its utility in pocket milling and multi-axis toolpaths. Right-hand cut, right-hand flute configuration is the standard orientation for conventional and climb milling on vertical machining centers. No chipbreaker geometry means this tool is best applied in continuous, consistent-depth cuts rather than interrupted or roughing passes.

Key Features

• Micrograin solid carbide construction for wear resistance and edge retention
• 40-degree helix angle promotes smooth chip flow and reduced heat buildup
• Centercutting design supports direct plunge entry into the workpiece
• Stub-length (2 inch OAL) geometry maximizes rigidity and minimizes deflection
• Uncoated finish suitable for aluminum, brass, and general-purpose steel applications
• 4-flute configuration balances chip clearance with surface finish quality

Compatibility

Designed to seat in any standard 3/8 inch end mill holder or ER collet system. Shank diameter tolerance of -0.0001 to -0.0004 inches ensures a secure, repeatable fit in precision collet chucks on CNC and manual milling machines.

Installation Notes

Install and remove end mills only with the machine spindle fully stopped and the control in an e-stop or locked-out state per OSHA lockout/tagout procedures. Seat the shank to the full recommended engagement depth in the collet before torquing the collet nut. Inspect the cutting edges and shank for chips or runout before each use. Do not exceed the tool manufacturer's recommended speeds and feeds for the specific workpiece material.