Osg 5401400 Square End Mill 11/16 in 4 Flute Cobalt

Product Description

The OSG 5401400 is a square end mill designed for general-purpose milling operations in metal fabrication and machining environments. Built from M42 cobalt high-speed steel, this tool handles harder workpiece materials and maintains cutting edge integrity under elevated heat. It features a 11/16 inch (0.6875 inch) cutting diameter, a 4-flute spiral configuration with a 30-degree helix angle, and right-hand cut with right-hand flute geometry. The 1/2 inch shank diameter fits standard end mill holders and collet chucks. This tool is intended for use by machinists and tool-and-die professionals on manual and CNC milling machines.

This end mill suits slotting, peripheral milling, and profiling passes on ferrous and non-ferrous materials where cobalt tooling is specified for improved hardness and heat resistance. With a 1-5/8 inch length of cut and a 3-5/8 inch overall length, it fits regular-reach applications without extended toolholding. It is not center-cutting, so plunge milling is not an appropriate application. The Series 540 designation places it within OSG's standard cobalt end mill line, uncoated and ready for use with appropriate cutting fluid.

Key Features

• M42 cobalt construction for improved hot hardness over standard HSS
• 4-flute spiral design with 30-degree helix for balanced chip evacuation and finish quality
• Right-hand cut, right-hand flute geometry — standard orientation for conventional milling setups
• Uncoated surface — compatible with a wide range of cutting fluids and re-sharpenable
• Not center-cutting — suited for peripheral and slot milling, not plunge entry
• Regular length classification with 1-5/8 inch LOC fitting most standard workholding setups

Compatibility

Designed as a replacement or production-run end mill for standard 1/2 inch end mill holders, collet chucks, and Weldon-style holders used in vertical and horizontal milling machines. Compatible within OSG Series 540 cobalt end mill specifications.

Installation Notes

Installation should be performed by a qualified machinist following shop safety protocols. Secure the shank fully into the toolholder to the recommended engagement depth before tightening. Ensure the spindle is fully stopped and the machine is powered down before changing tooling. Verify runout with an indicator after seating to confirm proper alignment before beginning a cut.