Osg 1664700009 Thread Mill 4-40 Unc 2 Flute Solid Carbide

Product Description

The OSG 1664700009 is a solid carbide helical flute thread mill designed to cut 4-40 UNC internal threads in a single helical pass. With a 0.083-inch cutting diameter and a 40-tooth-per-inch pitch, it is built for small-diameter thread milling in tight-tolerance machining applications. The DLC-IGUSS coating reduces friction and extends tool life in demanding materials. The long-reach mill type and left-hand flute direction suit CNC machining centers where climb milling and chip evacuation are priorities. Machinists and toolroom technicians are the primary installers of this tooling.

This thread mill is used in precision machining environments where tapping is impractical or where thread quality demands are high. The 0.25-inch straight-cylindrical shank fits standard ER collet chucks and end mill holders on CNC machining centers. The 0.125-inch length of cut and 2-inch overall length give access to shallow thread depths in small bores. Typical applications include aerospace, medical device, and precision instrument components where 4-40 UNC threads are specified.

Key Features

• Solid carbide construction for rigidity and wear resistance in hardened and abrasive materials
• DLC-IGUSS coating reduces friction and extends tool life in dry or minimal-lubrication cutting
• Left-hand helical flute direction supports climb milling and efficient chip evacuation
• Long-reach mill type provides access to threads in recessed or hard-to-reach bore locations
• 0.083-inch cutting diameter sized for 4-40 UNC thread form at 40 TPI
• h6 shank diameter tolerance ensures consistent runout in precision collet and end mill holder setups

Compatibility

Designed for CNC machining centers capable of helical interpolation; fits 0.25-inch straight-cylindrical collet chucks and end mill holders; suited for cutting 4-40 UNC threads per the UNC thread standard.

Installation Notes

Installation and use should be performed by qualified machinists on CNC machining centers with helical interpolation capability. Verify spindle speed, feed rate, and helical pitch in the CAM program before cutting. Secure the shank fully in a precision collet or end mill holder to minimize runout. Inspect the cutting edges before each use and replace at first sign of chipping or wear to maintain thread quality.