Osg 5312100 Square End Mill 5/8 in 3 Flute Cobalt

Product Description

The OSG 5312100 is a cobalt square end mill designed for milling operations in ferrous and difficult-to-machine materials. Built to Series 531 standards, it features a 0.625 inch cutting diameter, a 1.625 inch length of cut, and a 3-flute spiral configuration with a 30-degree helix angle. The cobalt construction — specifically M42 grade — provides superior heat resistance over standard high-speed steel, making it well suited for harder alloy steels and stainless applications. This is a single-end, centercutting tool capable of plunge entry as well as peripheral and slot milling. It is installed and used by machinists and tool-and-die professionals in production and job shop environments.

This end mill fits standard machining centers, knee mills, and CNC vertical mills accepting a 0.625 inch straight shank. At 3.75 inches overall length with a regular length classification, it is appropriate for general-purpose milling at moderate depths. The right-hand cut and right-hand flute geometry follow conventional milling practice. The uncoated finish suits shops that prefer to apply their own lubricant strategy or work with materials where coatings offer minimal advantage. Compatible with collet chucks, end mill holders, and hydraulic toolholding systems sized for 0.625 inch shanks.

Key Features

• M42 cobalt construction for improved heat and wear resistance over standard HSS
• Centercutting design allows direct plunge entry without a pre-drilled hole
• 30-degree helix angle promotes smooth chip evacuation and reduced cutting forces
• 3-flute configuration balances chip clearance and surface finish
• Uncoated finish suitable for wet or mist coolant machining strategies
• Right-hand cut and right-hand spiral flute for conventional spindle operation

Compatibility

Designed for use in toolholders and collet systems accepting a 0.625 inch shank diameter; fits standard end mill holders, ER collets, and hydraulic chucks sized for 5/8 inch straight-shank tooling.

Installation Notes

Installation is performed by a machinist or toolroom technician. Ensure the spindle is fully stopped and the machine is in a safe, locked-out state before changing tooling. Insert the shank to full depth in the holder, meeting the minimum engagement recommended by the toolholder manufacturer, and torque the retention hardware per the holder specification. Verify runout with a dial indicator before cutting to protect both the tool and the workpiece.