Vargus 51591 Laydown Threading Insert 3ER20UN Vtx 20 Tpi

Product Description

The VARGUS 51591 is a solid carbide laydown threading insert designed for right-hand external UN thread cutting at 20 threads per inch (TPI). Manufactured in the 3ER insert style with a VTX grade designation, it carries a PVD-applied TiAlN coating for thermal resistance and extended tool life across a wide range of workpiece materials. The inscribed circle measures 9.53 mm (3/8 inch) and the insert thickness is 3.60 mm. This insert is intended for use on CNC lathes and turning centers by machinists and toolroom professionals performing precision external thread operations.

The 51591 is suited for external UN thread applications on materials spanning steel, stainless steel, cast iron, aluminum, non-ferrous alloys, and heat-resistant superalloys, corresponding to workpiece material codes H, K, M, N, P, and S. The 60-degree included angle and single tooth per side design make it appropriate for standard unified national thread forms in production and job-shop turning environments.

Key Features

• Solid carbide substrate with PVD TiAlN coating for wear resistance across diverse workpiece materials
• 3ER insert style, size code 3, with 60-degree included angle for UN thread form accuracy
• 20 TPI cutting geometry for right-hand external UN threads
• Inscribed circle of 9.53 mm (3/8 inch) for standard toolholder compatibility
• Universal primary workpiece material rating covering ferrous, non-ferrous, and superalloy materials
• Meets ANSI B1.1:74 thread standard and manufactured under ISO 9001:2008 quality system

Compatibility

Designed as an OEM-style replacement threading insert for toolholders accepting 3ER-style laydown inserts with a 3/8-inch inscribed circle. Specific toolholder compatibility should be verified against the toolholder manufacturer's insert specification chart.

Installation Notes

Installation and indexing of threading inserts should be performed by qualified machinists with the machine in a fully locked-out and tagged-out state. Seat the insert firmly in the pocket and torque the clamp screw using the toolholder manufacturer's specified wrench to avoid cracking the carbide substrate. Inspect the insert pocket for chips or debris before seating. Follow your facility's applicable machining safety procedures and toolholder OEM guidelines when setting cutting parameters.