Accupro 12178756 Square End Mill 21/64 in 2 Flute Carbide

Product Description

The ACCUPRO 12178756 is a solid carbide square end mill designed for precision milling operations in metal, composite, and engineered material applications. It features a 21/64 inch (0.3281 inch) cutting diameter with a 7/8 inch (0.5625 inch) length of cut and a 3/8 inch shank diameter, giving it a compact profile suited to tight-tolerance work. The two-flute spiral geometry runs at a 40-degree helix angle with right-hand cut and right-hand flute direction. An nACRo finish on the cutting edges improves heat resistance and extends tool life in demanding machining environments. This tool is single-end, centercutting, and built from micrograin solid carbide stock.

This end mill is intended for use in CNC machining centers, manual mills, and high-speed spindle setups where a small-diameter, short-reach tool is required. The 2-1/2 inch overall length keeps runout low in applications that require close spindle-to-work proximity. The centercutting capability allows plunge entry without a pre-drilled hole. Machinists working in tool-and-die, aerospace component work, medical device production, and general precision shop environments will find this size range appropriate for finishing passes and fine detail work in ferrous and non-ferrous materials.

Key Features

• 21/64 inch cutting diameter with a mill diameter tolerance of +0.000 / -0.002 inches for tight-fit applications
• 40-degree helix angle spiral flute geometry for improved chip evacuation and surface finish
• nACRo coating provides elevated heat resistance and reduces tool wear in abrasive materials
• Centercutting design enables direct plunge entry without pilot drilling
• Micrograin solid carbide construction delivers rigidity and edge retention
• Right-hand cut and right-hand flute direction for standard spindle operation

Compatibility

Designed as a standard 3/8 inch shank square end mill compatible with any collet, end mill holder, or milling chuck accepting a 3/8 inch straight shank, with a shank diameter tolerance of -0.0001 / -0.0004 inches.

Installation Notes

Installation should be performed by a qualified machinist following shop safety protocols and machine tool manufacturer guidelines. Secure the shank fully within the holder to the minimum insertion depth recommended for the holder type, and verify runout with a dial indicator before initiating a cut. Ensure the spindle is at a complete stop and the machine is powered down before changing or inspecting the tool. Do not exceed the tool manufacturer's recommended feed and speed parameters for the workpiece material and coating type.