Osg 5420300 Square End Mill 1/4 in 4 Flute Cobalt Double End

Product Description

The OSG 5420300 is a cobalt square end mill designed for milling operations in metalworking and machining environments. Built from M42 cobalt high-speed steel, it delivers heat and wear resistance suited for cutting ferrous metals, stainless steels, and other tough materials. The tool measures 0.25 inches in cutting diameter with a 0.625-inch length of cut, a 0.375-inch shank diameter, and a 3.375-inch overall length. With 4 spiral flutes at a 30-degree helix angle and right-hand cut and flute direction, it produces clean, efficient chip evacuation during side milling and profiling passes.

This end mill is used in manual knee mills, CNC machining centers, and drill press setups for slot milling, profiling, and light pocket work on harder workpiece materials. The double-end design provides two usable cutting ends, extending tool life and reducing per-cut tooling cost. It fits production and tool room environments where M42 cobalt construction is preferred over carbide for interrupted cuts or setups with less-than-rigid fixturing. The Series 542 designation identifies it within OSGs standard cobalt end mill lineup.

Key Features

• M42 cobalt construction for elevated heat resistance compared to standard HSS
• Double-end design provides two cutting ends per tool
• 4 spiral flutes with 30-degree helix angle for efficient chip flow
• Right-hand cut and right-hand flute direction for standard spindle operation
• Uncoated finish suitable for use with cutting fluids on ferrous materials
• Regular length designation fits standard toolholders without extended-reach concerns

Compatibility

Designed as an OEM-style replacement or direct-use cutting tool for machining centers and manual mills accepting a 3/8-inch straight shank end mill holder or collet.

Installation Notes

Installation is performed by machinists using an appropriate collet chuck or end mill holder rated for the 0.375-inch shank diameter. Ensure the spindle is fully stopped and locked out before installing or removing the tool. Verify runout with a dial indicator after seating in the holder, as excessive runout accelerates flute wear. This tool is not center-cutting and should not be used for direct plunge entry into solid material.