Heli-coil 7552-5 Thread Insert Hand Install Tool 5/16-24

Product Description

The HELI-COIL 7552-5 is a hand installation tool designed to install wire thread inserts into pre-tapped holes. It uses a Prewinder Type II mechanism that pre-winds the insert onto the mandrel before driving it into the receiving hole. The tool is built for 5/16-24 UNF thread inserts and accepts both free-running and locking insert styles. With a prewinder body diameter of 0.625 inches and a prewinder length of 4.625 inches, it is sized for single-handed operation in the field or at the bench. Licensed mechanics, maintenance technicians, and MRO professionals use this tool for thread repair and thread installation work across metal assemblies.

This tool is suited for applications where a 5/16-24 UNF wire thread insert must be installed by hand without a power driver. Typical scenarios include thread repair on stripped fastener holes in aluminum, cast iron, or steel housings, as well as new-installation work in production environments where power tools are restricted. The spinner diameter of 3.719 inches provides enough grip surface for controlled manual torque during insert seating. It is used across HVAC equipment, plumbing fixtures, electrical enclosures, and general industrial assemblies where threaded insert repair is required.

Key Features

• Prewinder Type II design pre-winds the insert onto the mandrel before installation, reducing cross-threading risk
• Compatible with both free-running and locking wire thread insert styles
• Sized for 5/16-24 UNF thread standard
• Prewinder body diameter of 0.625 inches fits standard access clearances
• Spinner diameter of 3.719 inches allows controlled manual torque application
• Prewinder length of 4.625 inches suits bench and in-place installation scenarios

Compatibility

Designed for use with HELI-COIL and compatible 5/16-24 UNF wire thread inserts in both free-running and locking configurations. Consult insert manufacturer documentation to confirm mandrel-to-insert fit before use.

Installation Notes

A licensed mechanic or maintenance technician should confirm the receiving hole is tapped to the correct UNF oversize specification before insert installation. The assembly should be secured or supported to prevent movement during manual driving. Do not use power tools with this hand installation tool. Follow insert manufacturer torque guidelines and verify proper insert seating depth after installation.