Vargus 51271 Threading Insert 3ER12UNJ Vkx 12 Tpi Solid Carbide

Product Description

The VARGUS 51271 is a solid carbide laydown threading insert designed for external UNJ thread forms at 12 threads per inch (TPI). Built to the 3ER style with a 3/8-inch inscribed circle, this insert carries a TiN (titanium nitride) PVD coating applied over a solid carbide substrate for extended edge life across a wide range of workpiece materials. The 60-degree included angle matches the UNJ thread standard profile, making it suitable for aerospace and high-reliability fastener thread production. Licensed machinists and CNC lathe operators use this insert in production threading applications where thread-root radius and form accuracy are critical to specification.

This insert is rated for universal workpiece material compatibility, covering cast iron, non-ferrous metals, non-metallic materials, steel, stainless steel, and high-temperature alloys - corresponding to ISO material groups H, K, M, N, P, and S. It is suited for external threading operations on CNC lathes and turning centers in both job-shop and production environments where UNJ thread forms are required by engineering drawing or military specification. Right-hand cutting orientation is standard for this configuration.

Key Features

• 3ER insert style with 3/8-inch inscribed circle for standard laydown toolholders
• Solid carbide construction with PVD TiN coating for wear resistance and extended tool life
• 60-degree included angle - correct profile for UNJ external thread forms
• 12 TPI external threading, right-hand cut
• Universal material compatibility: ISO groups H, K, M, N, P, and S
• Manufactured to ISO 9001:2008 and MIL-S-8879C standards

Compatibility

Designed for use in 3ER-style laydown threading toolholders configured for external UNJ thread applications. Conforms to MIL-S-8879C, making it appropriate for aerospace and defense threading operations requiring UNJ form compliance.

Installation Notes

Installation is performed by a machinist or CNC tooling technician. Power down and lock out the machine before seating or changing the insert. Ensure the toolholder pocket and clamping screw are clean and free of chips before seating the insert to maintain accurate thread form geometry. Follow the toolholder manufacturer torque guidance for the clamping screw - do not overtighten, as carbide inserts are brittle and can fracture under excessive clamping load.