Seco 00077989 Laydown Threading Insert 20 Tpi Un

Product Description

The SECO 00077989 is a laydown threading insert designed for internal UN thread cutting at 20 threads per inch. Built from solid carbide with a micrograin structure and coated via PVD with a TiAlN/TiN finish under the CP500 grade designation, this insert delivers consistent edge life and wear resistance in demanding threading applications. The 60-degree included angle conforms to standard UN thread geometry, and the A2 chipbreaker promotes reliable chip control during internal threading operations. Licensed machinists and CNC lathe operators use this insert in Snap Tap-series toolholders for precision thread production.

This insert is suited for internal threading of stainless steel workpieces, classified under material code M. Right-hand cut orientation makes it appropriate for standard right-hand thread profiles in production and job-shop environments. The 3/8 inch inscribed circle and 0.1366 inch thickness position it for use in toolholders designed around the 16NR insert style. It is packaged individually but must be ordered in multiples of two. Typical applications include threading bores in stainless components across aerospace, medical, and general industrial machining.

Key Features

• Solid carbide micrograin substrate for high hardness and edge integrity
• PVD-applied TiAlN/TiN coating under CP500 grade for extended tool life in stainless steel
• 60-degree included angle for standard UN thread form compliance
• A2 chipbreaker geometry promotes chip evacuation in internal threading
• Right-hand cut for standard internal UN thread profiles
• ISO-standard insert geometry for consistent toolholder compatibility

Compatibility

Designed for use in 16NR-style Snap Tap series toolholders for internal threading operations. Confirm toolholder seat dimensions and insert style designation before installation.

Installation Notes

This insert is installed by qualified machinists or CNC operators. Power down and lock out the machine before seating or replacing inserts. Use the appropriate torx or insert-clamping wrench to secure the insert without over-tightening the clamping screw, and verify seating is flush before resuming cuts. Inspect the insert seat for chips or debris that could affect insert positioning and thread accuracy.