Scientific Cutting Tools TMI079-40HA Thread Mill 4-40

Product Description

The SCIENTIFIC CUTTING TOOLS TMI079-40HA is a helical flute thread mill designed for cutting internal 4-40 UNC threads in a single helical pass. Built from submicron-grade solid carbide and finished with an AlTiN+ coating, it delivers consistent thread form and extended tool life in ferrous and non-ferrous materials. The two-flute right-hand geometry produces a 0.0790 inch cutting diameter with a 0.1850 inch length of cut. At 2.5 inches overall length, this is a long-reach configuration suited for applications where clearance is limited. Installation and operation require a CNC machining center capable of helical interpolation.

This thread mill is used in precision machining environments where tapping is impractical or where a single tool must produce threads in multiple hole sizes. The 4-40 internal thread profile and long-reach body make it appropriate for small-fastener applications in electronics enclosures, instrument housings, and mechanical assemblies requiring fine UNC threads. It is intended for use by machinists and tooling specialists running CNC milling operations on production or prototype work.

Key Features

• Submicron-grade solid carbide construction for rigidity and wear resistance
• AlTiN+ coating improves heat resistance and extends tool life in dry or semi-dry cutting
• Two right-hand helical flutes for efficient chip evacuation in internal thread milling
• Long-reach design at 2.5 inches OAL allows access to recessed or deep hole locations
• Cuts 4-40 UNC internal threads at 40 TPI with a 0.0790 inch cutting diameter
• No coolant-through requirement simplifies toolholder selection

Compatibility

Designed as an OEM-style thread milling tool for CNC machining centers capable of helical interpolation and accepting a 1/4 inch straight shank toolholder.

Installation Notes

Thread mills require a CNC control capable of helical interpolation - confirm G-code support before programming. The 1/4 inch shank must be secured in a properly sized collet or end mill holder; verify runout before cutting to protect the small-diameter carbide tool. Power down the spindle and secure the workpiece before any tool change or inspection. Follow shop safety protocols and applicable OSHA machining guidelines when handling carbide tooling.