Osg 1664500411 Thread Mill 5/16 Unc 4 Flute Solid Carbide

Product Description

The OSG 1664500411 is a helical flute thread mill designed for cutting 5/16 UNC internal threads in solid carbide construction with a DUROREY coating. It features 4 flutes and a long-reach thread mill geometry, making it well-suited for precise thread milling operations in ferrous and non-ferrous materials. The cutting diameter is 0.224 inches with a length of cut of 0.1667 inches and an overall length of 3.5 inches. A 3/8-inch shank diameter provides rigid tool holding. Coolant-through capability supports chip evacuation during deep or tight-tolerance thread milling cuts. This tool is installed by machinists and CNC operators working in production or job-shop environments.

This thread mill is used in CNC machining centers for generating 5/16 UNC threads at 18 teeth per inch. The long-reach design allows access to threads in recessed or deep-pocket features where standard-length tools cannot reach. It is appropriate for use in aerospace, automotive, tooling, and general metalworking applications where thread accuracy and surface finish are critical. The helical flute geometry improves chip flow and reduces cutting forces compared to straight-flute designs.

Key Features

• Solid carbide construction for rigidity and wear resistance
• DUROREY coating for extended tool life in ferrous materials
• Coolant-through design aids chip evacuation in deep thread features
• Long-reach thread mill type for access to recessed thread locations
• 4 helical flutes for improved chip flow and reduced cutting forces
• 18 TPI cutting profile matched to 5/16 UNC thread standard

Compatibility

Designed for CNC machining centers capable of helical interpolation; compatible with 3/8-inch tool holders and collet chucks used in standard milling setups for 5/16 UNC thread milling applications.

Installation Notes

Thread mills of this type are installed by qualified CNC machinists and require a machining center with helical interpolation capability. Confirm tool holder runout is within acceptable tolerance before running to protect the carbide cutting edges. Do not use in manual milling machines. Always verify thread pitch programming matches the 18 TPI specification before cutting.