Cleveland C39640 Square End Mill 3/16 in 3 Flute Hss

Product Description

The CLEVELAND C39640 is a 3-flute square end mill designed for material removal and profile milling in metalworking applications. Manufactured from high speed steel with a bright/uncoated finish, it features a 3/16 inch cutting diameter, a 1/2 inch length of cut, and a 2-3/8 inch overall length. The 30-degree right-hand spiral helix promotes efficient chip evacuation and reduces cutting forces. The straight-cylindrical shank with Weldon flat accepts standard end mill holders and collet chucks. Center-cutting geometry allows plunge entry in addition to peripheral and slot milling operations. This tool is suited for machinists and tool and die technicians working in job shop and production environments.

The C39640 is rated for use in cast iron, non-ferrous metals, and steel. Its regular-length profile makes it well suited for general-purpose slotting, profiling, and step milling where extended reach is not required. The 3/8 inch shank diameter fits standard R8, ER, and side-lock holders commonly found in knee mills and CNC machining centers. Single-end construction means the tool is replaced rather than re-indexed when the cutting end is worn.

Key Features

• 3/16 inch cutting diameter with 1/2 inch length of cut for controlled depth passes
• 3-flute geometry balances chip clearance and surface finish on steel and cast iron
• 30-degree right-hand helix reduces cutting pressure and promotes smooth chip flow
• Center-cutting design permits direct plunge milling without pre-drilling
• Straight-cylindrical shank with Weldon flat for positive retention in side-lock holders
• Bright/uncoated finish — suitable for re-sharpening without coating removal

Compatibility

Designed for use with cast iron, non-ferrous metals, and steel workpieces. Fits standard 3/8 inch end mill holders, collet chucks, and Weldon-flat side-lock holders on manual and CNC milling machines.

Installation Notes

Installation is performed by qualified machinists following standard toolroom practice. Secure the shank fully in the holder and tighten to the holder manufacturer's torque specification before engaging the spindle. Ensure the machine spindle is fully stopped and locked out before changing or inspecting the end mill. Verify runout with a dial indicator after installation to confirm proper seating and extend tool life.