Carmex 12I18UNMT7 Carbide Thread Mill Insert 18 Tpi

Product Description

The CARMEX 12I18UNMT7 is a carbide thread mill insert designed for internal UN threading operations at 18 teeth per inch (TPI). Built from submicron carbide in the MT7 grade, it carries a TiAlN coating that reduces heat buildup and extends tool life in demanding cutting environments. The insert measures 0.114 inches (2.9 mm) thick and follows the 12I insert style. It is installed by machinists and tool-and-die professionals in CNC thread milling applications where precise, repeatable internal thread profiles are required.

This insert is suited for internal UN thread milling on machining centers and multi-axis CNC equipment. The UN thread standard conforms to ANSI B1.1-1989, making it appropriate for standard unified inch thread forms in both production and job-shop environments. The non-conical geometry supports straight thread milling passes on through-holes and blind bores across a range of ferrous and non-ferrous workpiece materials.

Key Features

• Submicron carbide substrate in MT7 grade for consistent edge integrity
• TiAlN coating provides thermal resistance and reduced flank wear in high-speed threading
• 18 TPI for standard unified inch internal thread profiles
• Conforms to ANSI B1.1-1989 UN thread standard
• 0.114 inch (2.9 mm) insert thickness for precise seating in compatible toolholders
• Non-conical geometry for straight-wall internal thread milling

Compatibility

Designed as an OEM-style replacement insert for thread mill bodies accepting the 12I insert style in internal UN threading applications.

Installation Notes

Installation is performed by qualified machinists following standard CNC tooling change procedures. Ensure the spindle is fully stopped and machine power is locked out before seating or removing inserts. Use the correct torx or hex key per the toolholder manufacturer specification to secure the insert without over-torquing the clamping screw. Verify insert seating and runout before resuming cutting operations.