Osg 5365100 Square End Mill 1 in 3 Flute Cobalt Long

Product Description

The OSG 5365100 is a cobalt square end mill designed for milling operations in ferrous and hard materials where high-speed steel would wear prematurely. Built from M42 cobalt high-speed steel, this single-end tool runs a 1-inch cutting diameter with a 4-inch length of cut, making it well-suited for deep-pocket and slotting work where extended reach is required. The 3-flute geometry balances chip evacuation with rigidity, and the 30-degree spiral helix promotes smooth cutting action and reduced chatter. The uncoated finish keeps regrinding straightforward. This tool is classified as a long-series end mill and is installed by machinists and tool-and-die professionals in vertical machining centers and manual mills.

The OSG 5365100 fits standard applications in job shops, maintenance machining, and production environments where a 1-inch cobalt end mill is required for steel, stainless, cast iron, or similar materials. The 1-inch shank diameter suits R8, CAT, BT, and other common spindle toolholders designed for 1-inch straight shanks. The 6.5-inch overall length provides the clearance needed for deep-reach setups without requiring extension holders. Centercutting capability allows direct plunge entry into the workpiece.

Key Features

• M42 cobalt construction for improved heat and wear resistance over standard M2 HSS
• 3-flute design balances chip clearance and core strength for slotting and pocketing
• 30-degree helix angle reduces cutting forces and improves surface finish
• Centercutting geometry enables direct plunge milling without a pilot hole
• Long-series length of cut (4 inches) supports deep-cavity work
• Right-hand cut, right-hand flute, uncoated — straightforward to resharpen

Compatibility

Designed as an OEM-style replacement or direct-application long-series square end mill for any setup requiring a 1-inch diameter, 1-inch shank, 3-flute cobalt tool in OSG Series 536.

Installation Notes

Installation should be performed by a qualified machinist. Secure the shank in a properly sized collet, end mill holder, or Weldon-style holder to the manufacturer-specified engagement depth before operating. Verify spindle runout is within acceptable tolerance before cutting; excessive runout accelerates edge wear on cobalt tooling. Always confirm the machine spindle is fully stopped and locked out before changing or inspecting the tool.