Osg 5956100 Tapered End Mill 1/4 in Cobalt 3 Flute

Product Description

The OSG 5956100 is a cobalt tapered end mill designed for machining tapered profiles, slots, and contoured features in metalworking and toolroom applications. Built from M42 cobalt high-speed steel, it delivers increased heat and wear resistance compared to standard HSS tooling. The square end geometry produces flat-bottomed cuts, and the centercutting design allows plunge entry. Key dimensions include a 1/4 inch small end diameter, 3/8 inch shank diameter, 3/4 inch length of cut, and 2-1/2 inch overall length. With 3 right-hand spiral flutes at a 25-degree helix angle, the tool evacuates chips efficiently and maintains a clean finish across a range of work materials. It arrives uncoated and is part of OSG Series 595.

This tapered end mill is suited for mold and die work, fixture fabrication, and general precision machining where a 5-degree taper per side is required. It is appropriate for CNC machining centers and manual knee mills running ferrous and non-ferrous metals. The 3/8 inch straight shank fits standard end mill holders and collet chucks. It is a practical choice for tool and die makers, machinists, and maintenance shops that need a reliable cobalt taper mill in a compact size.

Key Features

• 5-degree taper per side for consistent tapered profile cutting
• M42 cobalt HSS construction for improved red hardness and wear resistance over standard HSS
• Centercutting design allows direct plunge entry without pre-drilling
• 3 right-hand spiral flutes with 25-degree helix angle for efficient chip evacuation
• Square end geometry produces flat-bottomed tapered slots and pockets
• Uncoated finish suitable for use with cutting fluids across a broad material range

Compatibility

Designed as an OEM-style replacement or new-installation tapered end mill for use in standard 3/8 inch end mill holders and collet chuck systems on CNC and manual milling machines.

Installation Notes

Installation should be performed by a qualified machinist following shop safety procedures. Ensure the machine spindle is fully stopped and locked out before mounting or removing the tool. Seat the shank fully into the holder and torque the set screw or collet nut to the toolholder specification. Confirm runout with a dial indicator before beginning a cut, and apply an appropriate cutting fluid for the workpiece material.