Carmex MT0250C0716UN Thread Mill 3/8-16 Internal Solid Carbide

Product Description

The CARMEX MT0250C0716UN is a solid carbide helical flute thread mill designed for cutting internal 3/8-16 UNC threads in a single helical pass. With a cutting diameter of 0.236 inches, a 1/4-inch shank, and a TiAlN coating, this tool handles the thermal and abrasive demands of thread milling in steel, stainless, and hardened materials. The three right-hand flutes provide smooth chip evacuation and stable cutting action. At 2.5 inches overall length with a 0.66-inch length of cut, it fits standard CNC machining center toolholders used in production and job-shop environments. Machinists and CNC programmers select this tool for precise internal thread generation without the breakage risk associated with tapping.

This thread mill is suited for CNC machining centers running 3/8-16 UNC internal thread programs in ferrous and non-ferrous workpieces. The helical interpolation approach makes it effective in blind holes, through holes, and thin-walled parts where tap breakage or extraction would be costly. The 1.8-inch shank length provides adequate reach for most standard fixture setups. It is commonly used in aerospace, general machining, and mold-and-die work where thread quality and tool reliability are priorities. A single tool covers the full thread depth in one interpolated arc pass, reducing cycle time compared to multiple-pass methods.

Key Features

• Solid carbide construction in material grade MT7 for rigidity and wear resistance
• TiAlN coating extends tool life in high-temperature cutting conditions
• Three right-hand helical flutes for efficient chip removal in internal threading
• 0.236-inch cutting diameter sized for 3/8-16 UNC internal thread profile
• No coolant-through design - uses flood or mist coolant applied externally
• Single-tool solution for full thread depth via CNC helical interpolation

Compatibility

Designed for use on CNC machining centers capable of helical interpolation, producing 3/8-16 UNC internal threads. Requires a 1/4-inch straight-shank toolholder such as a collet chuck or end mill holder.

Installation Notes

Installation and operation should be performed by a qualified CNC machinist or tooling specialist. Secure the 1/4-inch shank in a properly sized collet or end mill holder and verify runout before cutting. Program the machine for helical interpolation using the correct thread pitch and cutting diameter offset per the tool manufacturer guidelines. Do not use this tool in manual or non-CNC drilling equipment.