Accupro 931-20250 Internal Thread Mill M20x2.5 4 Flute

Product Description

The ACCUPRO 931-20250 is a solid carbide helical flute thread mill designed for cutting internal M20x2.5 metric coarse threads. It features four flutes and a TiAlN coating, which improves heat resistance and extends tool life in demanding cutting conditions. The cutting diameter measures 0.4701 inches and the length of cut is 1.2598 inches. The shank diameter is 12.00 mm. This tool is intended for use by machinists and toolroom professionals on CNC machining centers capable of helical interpolation.

This thread mill is suited for internal threading operations in a range of ferrous and non-ferrous materials where a single tool is required to produce a complete M20x2.5 thread form. The micrograin carbide substrate supports use in harder workpiece materials and at higher cutting speeds compared to standard carbide grades. No coolant-through capability is present, so external coolant delivery should be applied when required by the material or operation. Typical applications include job shop, die and mold, and production machining environments.

Key Features

• Solid micrograin carbide construction for rigidity and edge retention
• TiAlN coating for elevated heat resistance and extended tool life
• 4-flute helical geometry for internal thread milling via CNC interpolation
• Cuts M20x2.5 metric coarse threads in a single helical pass
• Cutting diameter of 0.4701 inches with a 1.2598-inch length of cut
• No coolant-through — external coolant application required

Compatibility

Designed for use on CNC machining centers capable of helical interpolation; produces M20x2.5 metric coarse internal threads with a minimum nominal diameter of 0.7874 inches (20.00 mm).

Installation Notes

This tool is installed by a machinist in a compatible tool holder on a CNC machining center. Confirm runout and holder concentricity before use, as excessive runout will degrade thread quality and reduce tool life. Program the toolpath for helical interpolation at the correct pitch and diameter offset per the M20x2.5 thread specification. Do not use this tool in manual machines or drilling operations.