Scientific Cutting Tools TMLR4-.5MMA Thread Mill M4x0.5

Product Description

The SCIENTIFIC CUTTING TOOLS TMLR4-.5MMA is a helical flute thread mill designed for cutting internal M4x0.5 metric fine threads in a single helical pass. Built from submicron-grade solid carbide and finished with an AlTiN+ coating, it handles hard and abrasive workpiece materials where high-speed steel tooling would wear prematurely. The three-flute, right-hand helical design produces clean thread forms while managing chip evacuation in blind and through-hole applications. With a 0.12-inch cutting diameter and a 2.5-inch overall length, this is a long-reach tool suited for deep or obstructed thread locations that standard-length mills cannot access. Machinists and CNC programmers in precision machining, aerospace, and mold-and-die shops are the primary users.

This thread mill is applied in CNC machining centers where M4x0.5 internal threads are required in materials such as hardened steels, stainless, titanium, and cast iron. The long-reach geometry allows threading in recessed bores or pockets where a tap would risk breakage or cannot reach. The 0.25-inch shank diameter fits standard ER collet chucks and tool holders commonly found in vertical and horizontal machining centers. Because one tool cuts the full thread form via interpolation, a single TMLR4-.5MMA can produce multiple thread sizes close to M4x0.5 with appropriate CNC offset adjustments, reducing tool inventory requirements.

Key Features

• Submicron-grade solid carbide substrate for rigidity and extended tool life in hard materials
• AlTiN+ coating provides high-temperature oxidation resistance and reduced friction at the cutting edge
• Three helical flutes in a right-hand direction for efficient chip evacuation during interpolation
• Long-reach design with 2.5-inch overall length and 0.12-inch cutting diameter accesses deep or recessed thread locations
• Cuts M4x0.5 metric fine internal threads with a minimum nominal bore diameter of 0.1575 inches (4.00 mm)
• No coolant-through requirement; external flood or mist cooling is applicable

Compatibility

Designed for use in CNC machining centers with helical interpolation capability. Accepts a 0.25-inch shank for use with standard ER or end-mill-style collet holders. Intended for M4x0.5 metric fine internal thread milling in workpieces with a minimum nominal bore diameter of 4.00 mm (0.1575 inches).

Installation Notes

A licensed machinist or CNC programmer should verify helical interpolation parameters before running the tool. Secure the shank in a balanced, properly torqued collet holder and confirm runout is within acceptable limits before cutting, as excessive runout accelerates edge wear on carbide thread mills. Power down the spindle and follow lockout-tagout procedures before changing or inspecting the tool. Do not use this tool for tapping cycles; it is designed exclusively for CNC helical interpolation thread milling.