Heli-coil 4934 Thread Repair Kit 5/8-11 Unc 54 Inserts

Product Description

The HELI-COIL 4934 is a multi-size UNC thread repair kit designed to restore damaged or stripped internal threads in metal components. The kit covers six thread sizes ranging from 1/4-20 up to 5/8-11, making it a practical all-in-one solution for shops and field technicians who encounter thread damage across a variety of fastener sizes. A total of 54 threaded inserts are included alongside a drill, tap, and installation tool for each size, so the technician has everything needed to complete a proper repair without sourcing additional tooling. The inserts follow the Unified National Coarse standard and are suited for production repair, maintenance, and service work where thread integrity is critical.

This kit is used across mechanical, HVAC, plumbing, and electrical trade applications wherever UNC fastener threads have been stripped, cross-threaded, or damaged in parent material. It is well suited to residential and light commercial service environments where technicians work on equipment housings, brackets, panels, and mechanical assemblies with 1/4-20 through 5/8-11 fastener threads. The included drill, tap, and installation tool for each thread size allow a complete repair to be performed on-site without returning a component to a machine shop.

Key Features

• Covers six UNC thread sizes: 1/4-20, 5/16-18, 3/8-16, 7/16-14, 1/2-13, and 5/8-11
• 54 threaded inserts total across all six sizes
• Includes drill, tap, and installation tool - no additional tooling required
• Threaded insert style repair restores full thread strength in parent material
• UNC thread standard for broad compatibility with standard inch-series fasteners
• Self-contained kit format suitable for field service or shop use

Compatibility

Designed for repairing UNC internal threads in metal components using threaded insert-style repair across six standard inch-series thread sizes from 1/4-20 minimum to 5/8-11 maximum.

Installation Notes

Thread repair inserts should be installed by a qualified technician following the drill, tap, and insert sequence using the tools provided in the kit. The parent material must be drilled to the specified oversize diameter and tapped before the insert is driven in with the installation tool. Always de-energize, depressurize, or isolate the component or system before performing thread repair work on structural or pressure-bearing fastener locations. Do not exceed the drill or tap specifications for the target thread size as doing so can enlarge the parent bore beyond usable limits.