Osg 5573100 Square End Mill 3/4 in 4 Flute Cobalt Extra Long

Product Description

The OSG 5573100 is a cobalt square end mill designed for general-purpose milling operations across a wide range of ferrous and non-ferrous materials. Built to Series 557 specifications, this extra-long tool features a 0.75 inch mill diameter, a 4 inch length of cut, and a 6.25 inch overall length that gives machinists extended reach in deep-pocket and stepped-workpiece applications. The M42 cobalt construction provides superior heat and wear resistance compared to standard high-speed steel, making it suitable for harder alloys and demanding cycle times. Four flutes in a spiral configuration with a 30-degree helix angle promote efficient chip evacuation and a smooth cutting action on roughing and semi-finishing passes.

This end mill is suited for vertical machining centers, knee mills, and manual milling machines handling production or job-shop work. The extra-long length of cut range is well matched to deep-slot milling, profiling, and plunge operations where standard-length tools cannot reach the full feature depth. Right-hand cut and right-hand flute geometry follow conventional mill spindle direction. The uncoated finish makes it straightforward to inspect for wear and allows for regrinding when the cutting edges dull. Machinists working in tool rooms, fabrication shops, and production environments will find this a reliable workhorse for general milling tasks.

Key Features

• M42 cobalt construction for improved heat resistance and tool life over standard HSS
• 4 inch length of cut for extended reach in deep-pocket and stepped-workpiece setups
• 30-degree spiral helix angle promotes efficient chip evacuation and reduced chatter
• Four-flute design balances material removal rate with surface finish quality
• Right-hand cut, right-hand flute geometry for conventional spindle direction
• Uncoated finish allows easy wear inspection and supports regrinding

Compatibility

OSG Series 557 extra-long cobalt square end mills are designed as direct-fit tooling for standard 3/4 inch collet chucks, end mill holders, and side-lock arbors used on vertical and horizontal milling machines.

Installation Notes

Installation should be performed by a qualified machinist following the machine tool manufacturer's tooling guidelines. Secure the 3/4 inch shank fully into the holder and torque the retention mechanism per the holder manufacturer's specification before initiating any spindle operation. Note that this end mill is not center-cutting and is not suitable for direct axial plunge entry into solid material. Confirm workholding and fixture rigidity before engaging extended-reach tooling, as deflection risk increases with length of cut.