Irwin 6520ZR Hex Rethreading Die 1/4-20 Unc Right Hand

Product Description

The IRWIN 6520ZR is a hex rethreading die designed to restore damaged or corroded external threads to their original specification. Made from carbon steel, this die cuts a 1/4-20 UNC right-hand thread profile and features a 1-inch hex body for use with a standard wrench. Rethreading dies like this one are used by plumbers, electricians, HVAC technicians, and maintenance mechanics to salvage threaded fasteners and fittings on equipment and pipe connections without full replacement. The 1/4-20 UNC designation identifies the thread as 1/4-inch diameter with 20 threads per inch, a coarse unified national thread standard common across trade and industrial fastener applications.

This rethreading die is suited for field and shop use wherever 1/4-20 UNC threads on bolts, studs, or fittings have been cross-threaded, corroded, or otherwise damaged. It is commonly used in equipment repair, panel and fixture reassembly, and general mechanical maintenance across residential, commercial, and light industrial settings. The hex body allows use with an adjustable wrench or open-end wrench without a specialized die stock handle, making it practical for tight or congested work areas.

Key Features

• Restores damaged 1/4-20 UNC external threads to original specification
• Carbon steel construction for durability on standard fastener materials
• 1-inch hex body drives with a standard open-end or adjustable wrench
• Right-hand thread direction matches standard fastener orientation
• Compact form factor suits field repair and confined work areas

Compatibility

Designed for use on 1/4-20 UNC right-hand external threads on bolts, studs, and threaded rod. Fits any standard 1-inch hex driver or wrench.

Installation Notes

Rethreading dies are typically used by licensed mechanical, HVAC, plumbing, or electrical tradespeople during equipment service or repair. Before rethreading, de-energize equipment and relieve any pressure or fluid from the system as applicable. Apply cutting oil or thread lubricant to the die and the fastener to reduce heat and improve thread quality. Advance the die slowly with consistent pressure and back off periodically to clear debris.