Osg 5273100 3/4 Inch 2 Flute Cobalt Square End Mill

Product Description

The OSG 5273100 is a cobalt square end mill designed for milling operations that demand durability and heat resistance beyond standard high-speed steel tooling. Built from M42 cobalt steel, this end mill features a 0.750 inch cutting diameter, a 1.625 inch length of cut, and a 30-degree spiral helix angle. It is centercutting, allowing direct plunge entry into workpieces. The right-hand cut and right-hand flute configuration suits standard spindle setups. With a 5.375 inch overall length and 0.750 inch shank diameter, this tool fits directly into standard ER or end mill holders. Machinists and tool-and-die professionals install this type of tooling on vertical and horizontal CNC mills as well as manual knee mills.

This end mill is suited for general-purpose slot milling, profiling, and pocketing on ferrous and non-ferrous materials where cobalt tooling is preferred over carbide for toughness and regrindability. The two-flute geometry provides good chip clearance in slotting applications and softer materials. The uncoated finish makes it straightforward to regrind in-house. It falls within OSG Series 527, a regular-length product line intended for standard reach milling work. A 3.375 inch reach length accommodates moderate-depth features without requiring extended tooling setups.

Key Features

• M42 cobalt steel construction for improved heat and wear resistance over standard HSS
• Centercutting design allows direct plunge milling without pre-drilling
• 30-degree helix angle promotes smooth chip evacuation and reduces cutting forces
• Two-flute geometry maximizes chip clearance in slotting and deep-pocket applications
• Uncoated finish supports in-house regrinding to extend tool life
• Right-hand cut and right-hand flute — compatible with standard CNC and manual mill spindles

Compatibility

Designed as an OEM-style cutting tool for use in standard 3/4 inch end mill holders, collet chucks, and ER-style toolholders on vertical and horizontal milling machines. Part of OSG Series 527 regular-length square end mills.

Installation Notes

Installation and tool changes should be performed with the machine powered off and the spindle fully stopped. Secure the shank fully within the holder to the recommended gauge line before torquing the set screw or collet nut. Machinists should verify runout with a dial indicator after mounting to prevent premature edge wear. Follow the machine tool manufacturer guidelines and applicable shop safety standards when setting feeds and speeds for cobalt tooling.