Irwin 9427 Hex Rethreading Die 5/16-18 Unc Right Hand

Product Description

The IRWIN 9427 is a hex rethreading die designed to restore damaged or corroded external threads on fasteners and threaded rod. Made from carbon steel, it handles 5/16-18 UNC right-hand threads and seats in a standard 1-inch hex holder or wrench for controlled torque during use. This die is a compact, field-serviceable tool used by plumbers, HVAC technicians, electricians, and general tradespeople to salvage bolts, studs, and fittings without full replacement. It follows UNC thread standards and is suited for both shop bench work and on-site repair tasks where restoring thread integrity is faster than sourcing new hardware.

This rethreading die is applicable in any trade setting where 5/16-18 UNC threaded fasteners are in service. Common scenarios include restoring threads on equipment mounting bolts, panel studs, condensate pan hardware, pipe flange bolts, and similar field-encountered fasteners. It is particularly useful during equipment servicing when a fastener has been cross-threaded or corroded but the base material is still intact. The 1-inch hex profile fits standard adjustable wrenches and hex die stocks for easy single-tech operation.

Key Features

• Restores 5/16-18 UNC right-hand external threads on damaged or corroded fasteners
• Carbon steel construction provides sufficient hardness for use on standard steel and zinc-plated fasteners
• 1-inch hex profile seats in common die stocks and adjustable wrenches
• Compact form factor suits both toolbox carry and field use
• Right-hand thread direction matches the vast majority of standard UNC fastener applications

Compatibility

Designed for use on 5/16-18 UNC right-hand threaded fasteners in standard trade and mechanical applications. Fits any die stock or holder accepting a 1-inch hex die.

Installation Notes

Rethreading dies are typically used by hand with a die stock or adjustable wrench — power driving is not recommended as it increases the risk of cross-threading or die breakage. Clean the fastener of debris and apply a thread-cutting lubricant before running the die to reduce friction and extend die life. Inspect the fastener after rethreading to confirm thread engagement before torquing any mating nut or fitting. No special trade license is required, but proper technique is essential to avoid further damage to the base fastener.