Osg 5260400 Ball End Mill 0.3125 in 2 Flute Cobalt

Product Description

The OSG 5260400 is a single-end ball end mill designed for general milling applications in metal fabrication and machining environments. Built from M42 cobalt high-speed steel (HSS-Co), it delivers reliable cutting performance on steel and a broad range of secondary workpiece materials. The mill measures 0.3125 inches in diameter with a 0.75-inch length of cut and a 3.3125-inch overall length. The 30-degree medium helix and helical flute geometry support both roughing and finishing operations in a single tool, making it a practical choice for job shops and production machinists handling varied material types.

This end mill is suited for ferrous and non-ferrous milling tasks in manual and CNC machining centers. The extended reach design and 1.75-inch reach length make it useful for accessing deeper features or pockets where a standard-length tool would not clear the workpiece. The 3/8-inch Weldon flat shank provides positive drive and reduces the risk of slipping under cutting loads. Primary workpiece material is steel, with secondary compatibility covering stainless steel, cast iron, non-ferrous metals, superalloys, titanium, and hard materials.

Key Features

• M42 cobalt HSS construction for elevated heat and wear resistance compared to standard HSS
• Ball end geometry supports profiling, contouring, and 3D surface milling
• 30-degree medium helix with right-hand cut and right-hand flute direction
• Extended reach length of 1.75 inches for deeper feature access
• Weldon flat shank for secure tool holding and positive drive
• Bright/uncoated finish compatible with a wide range of cutting fluids and coolant strategies

Compatibility

Designed as a general-purpose OEM-style cobalt ball end mill suitable for use in standard 3/8-inch end mill holders and Weldon-style tool holders on manual mills and CNC machining centers.

Installation Notes

Installation should be performed by a qualified machinist following the machine tool manufacturer guidelines. Ensure the spindle is fully stopped and the machine is powered down before changing tooling. Secure the Weldon flat shank firmly in the tool holder to the specified clamping torque listed in the holder manufacturer documentation. Verify runout with a dial indicator before commencing cuts, particularly when profiling or working with tight-tolerance features.