Regal Cutting Tools 085909TM Thread Mill 5/16-18 3 Flute

Product Description

The REGAL CUTTING TOOLS 085909TM is a helical flute thread mill designed for cutting 5/16-18 UN threads in both internal and external applications. Built from sub-micrograin solid carbide and coated with AlTiN, it handles demanding cutting conditions in ferrous and non-ferrous materials. The 3-flute, right-hand flute geometry delivers clean thread profiles at 18 TPI. With a 0.235-inch cutting diameter and 0.625-inch length of cut, it suits tight-tolerance threading operations on machining centers and CNC mills. The 1/4-inch shank fits standard toolholders, and the 2.5-inch overall length provides adequate reach for most fixturing setups. Installed by machinists and tool-and-die professionals in production and job-shop environments.

This thread mill is suited for threading operations where a single tool must cut both internal and external 5/16-18 UN threads, eliminating the need to swap between a tap and an external threading tool. It is a practical choice for CNC machining centers running aluminum, steel, stainless, and similar materials where AlTiN coating helps manage heat and extend tool life. The 1.875-inch shank length provides stable clamping in collet chucks and end-mill holders. It is appropriate for both prototype work and production runs requiring consistent thread quality.

Key Features

• Cuts 5/16-18 UN threads in both internal and external applications with a single tool
• Sub-micrograin solid carbide construction for rigidity and wear resistance
• AlTiN coating reduces heat buildup and extends tool life in ferrous materials
• 3-flute, right-hand helical geometry for efficient chip evacuation
• 0.235-inch cutting diameter with 0.625-inch length of cut for controlled thread engagement
• No coolant-through design - compatible with external flood or mist coolant setups

Compatibility

Designed for use on CNC machining centers with standard 1/4-inch collet chucks or end-mill holders capable of accepting a 1/4-inch shank. Cuts 5/16-18 UN thread form in internal and external configurations.

Installation Notes

Thread mills require helical interpolation programmed at the CNC control - confirm the machine supports this cycle before setup. Secure the 1/4-inch shank with adequate collet clamping torque per the toolholder manufacturer's specification. Verify runout at the cutting diameter before starting production cuts, as excessive runout will directly affect thread quality and tool life. This tool does not have coolant-through capability, so direct external coolant or mist at the cutting zone to manage chip evacuation and heat.