Carmex 21E18UNMT7 Carbide Thread Mill Insert 18 Tpi

Product Description

The CARMEX 21E18UNMT7 is a carbide thread milling insert engineered for external UN thread applications. It carries the MT7 grade designation with a TiAlN finish, a submicron carbide substrate, and is rated at 18 teeth per inch. The insert style code is 21E with an insert size code of 21. This is a single-point thread milling insert intended for use in CNC machining centers where thread milling is preferred over tapping, particularly in hard materials or blind-hole situations. Installation and tooling setup is performed by machinists and CNC programmers working to ANSI B1.1-1989 UN thread standards.

This insert is designed for external thread milling operations following the UN thread standard, conforming to ANSI B1.1-1989. At 18 TPI, it suits a range of inch-series fastener thread profiles commonly found in industrial, mechanical, and structural assemblies. The TiAlN coating provides heat resistance suited to dry or semi-dry cutting conditions in steel, stainless, and similar alloys. Minimum order quantity is 5 inserts; package quantity is 1.

Key Features

• Submicron carbide substrate for edge stability in demanding materials
• MT7 manufacturer grade with TiAlN finish for high-temperature wear resistance
• 18 TPI external UN thread profile per ANSI B1.1-1989
• Insert style 21E, non-conical geometry
• 0.185 inch insert thickness
• Certified to ISO 9001:2015, ISO 14001:2015, ISO 13485:2016, ISO 45001, and CE standards

Compatibility

Designed as an OEM-style replacement insert for thread milling toolholders that accept the 21E insert style. Verify toolholder seat geometry and insert size code 21 compatibility before installation.

Installation Notes

Thread milling inserts are installed and indexed by qualified machinists or CNC tooling technicians. Power down and lock out the spindle before seating or indexing any insert. Use the manufacturer-specified torque wrench and clamping screw for the toolholder; do not over-tighten by hand. Confirm thread program lead, helical interpolation direction, and TPI settings in the CNC controller before cutting.