Vargus 51186 Threading Insert 3ER 11 Tpi Whitworth Carbide

Product Description

The VARGUS 51186 is a solid carbide laydown threading insert designed for external Whitworth thread cutting on CNC lathes and turning centers. It carries the VTX grade designation and a PVD-applied TiAlN coating, which improves heat resistance and edge life across a broad range of workpiece materials. The insert produces a 55-degree included angle consistent with the Whitworth thread form, runs at 11 threads per inch, and fits the 3ER insert style with a 3/8-inch (9.53 mm) inscribed circle and a thickness of 3.60 mm. It is intended for right-hand external threading operations and is sized for precision thread profiles in production and job-shop environments.

This insert is suited for external Whitworth threading on materials spanning steel, stainless steel, cast iron, nonferrous alloys, high-temperature alloys, and universal workpiece classifications covered by material codes H, K, M, N, P, and S. The Whitworth thread standard applies widely in maintenance, repair, and legacy equipment manufacturing where BSW and BSP thread forms are required. The 3ER geometry seats into standard 3ER laydown threading toolholders, making it a common choice for machinists running Whitworth thread programs on production turning equipment.

Key Features

• Solid carbide substrate with PVD TiAlN coating for extended tool life and thermal resistance
• 3ER insert style, 11 TPI, 55-degree included angle for Whitworth external thread profile
• Right-hand cutting geometry for standard external threading passes
• 9.53 mm (3/8 inch) inscribed circle, 3.60 mm thickness for 3ER toolholder compatibility
• Universal workpiece material rating covers steel, stainless, cast iron, nonferrous, and high-temp alloys
• Compliant with B.S.84:1956, DIN 259, ISO 9001:2008, and ISO 228/1:1982 standards

Compatibility

Designed for use in standard 3ER laydown threading toolholders requiring an 11 TPI Whitworth external insert with a 3/8-inch inscribed circle.

Installation Notes

Installation is performed by a qualified machinist or CNC tooling technician. Ensure the machine spindle is fully stopped and the toolholder is secured in the turret before seating or indexing the insert. Verify the insert seats flush in the pocket without rocking before tightening the clamping screw. Follow the toolholder manufacturer's torque guidance for the clamping fastener and confirm thread program parameters match the 11 TPI Whitworth specification before running the first pass.