Osg 4100000811 Thread Mill 1/4-20 Unc 3 Flute Solid Carbide

Product Description

The OSG 4100000811 is a solid carbide helical flute thread mill designed for cutting internal 1/4-20 UNC threads in a CNC machining environment. It features three right-hand flutes and a TiAlN-based EXO coating that improves wear resistance and heat dissipation during high-speed threading operations. The cutting diameter measures 0.18 inches with a length of cut of 0.402 inches, and the tool runs on a 1/4-inch shank diameter. At 3.0 inches overall length, it is sized for standard toolholder setups used in vertical and horizontal machining centers. This tool is installed and operated by machinists and CNC programmers working in precision machining, job shop, and production environments.

This thread mill is suited for internal thread milling applications requiring 1/4-20 UNC threads at 20 teeth per inch. It is used in ferrous and non-ferrous workpiece materials where a helical interpolation path is programmed into the CNC controller. Typical applications include blind-hole and through-hole threading in production runs and prototype work. The right-hand thread direction and right-hand flute direction are standard for conventional CNC thread milling cycles. No coolant-through capability is present, so flood or mist coolant at the spindle is the typical approach for chip evacuation and thermal management.

Key Features

• Solid carbide construction for rigidity and wear resistance in demanding threading operations
• EXO TiAlN coating reduces heat buildup and extends tool life in dry or semi-dry cutting conditions
• Three right-hand helical flutes provide efficient chip evacuation in internal thread milling
• 0.18-inch cutting diameter matched to 1/4-20 UNC thread geometry at 20 TPI
• 0.402-inch length of cut accommodates typical thread depth requirements for 1/4-20 fastener applications
• No coolant-through design simplifies toolholder selection and setup

Compatibility

Designed for use in CNC machining centers capable of helical interpolation for internal thread milling of 1/4-20 UNC right-hand threads. Compatible with standard 1/4-inch collet chucks and shrink-fit toolholders.

Installation Notes

Thread mills require a CNC control with helical interpolation capability — confirm the control supports the required G-code cycle before setup. Secure the 1/4-inch shank in a balanced, high-precision collet or shrink-fit holder to minimize runout. Spindle speed, feed rate, and radial engagement must be programmed to match the workpiece material and thread specification; consult the OSG Series 41000 cutting data guidelines for starting parameters. Inspect the cutting edges for chipping before each use, as carbide thread mills are sensitive to improper handling and runout beyond acceptable tolerances.