Heli-coil 7571-04-3B Mandrel Thread Insert Tool 4-40

Product Description

The HELI-COIL 7571-04-3B is a mandrel-type power installation tool designed for driving threaded wire inserts into pre-tapped holes. It accepts the 4-40 UNC thread size and is compatible with both bulk inserts and strip feed inserts, making it adaptable to different workflow setups on the shop floor or in the field. The mandrel engages the insert tang and winds the coil insert into the receiving thread without damaging the parent material. This tool is used by machinists, maintenance technicians, and assembly professionals who need a powered installation method for high-volume or repetitive insert work.

The 7571-04-3B is suited for applications where hand installation tools are too slow or where consistent installation depth and torque are required. The 4-40 UNC thread standard is common in light-gauge metal assemblies, electronics enclosures, and precision instrument housings. Both bulk-loaded and strip-feed insert formats are supported, so this tool integrates into automated or semi-automated production lines as well as bench repair operations.

Key Features

• Mandrel-drive design for powered installation of wire thread inserts
• Compatible with 4-40 UNC thread size inserts
• Accepts both bulk inserts and strip feed inserts
• Reduces installation time versus manual tang break-off tools
• Designed for repeatable, consistent insert seating depth

Compatibility

Compatible with HELI-COIL 4-40 UNC bulk inserts and strip feed inserts. Designed as an OEM-style power installation tool for use with standard 4-40 UNC thread wire inserts in typical production and repair applications.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician familiar with threaded insert systems. Ensure the parent material hole has been drilled and tapped to the correct HELI-COIL tap size for 4-40 UNC before driving the insert. Disconnect power to any assembly or machine before performing insert repair work on energized components. Follow the insert manufacturer guidelines for mandrel engagement and tang removal after installation.