Irwin 1835091 Tap Die Set 4-40 to 1/2-20 40 Pc

Product Description

The IRWIN 1835091 is a 40-piece tap and die set covering thread sizes from 4-40 through 1/2-20 in unified inch standards. Both taps and dies are manufactured from carbon steel with a bright finish. The hex-profile dies allow standard wrenches to seat firmly during threading operations. This set is suited for machinists, pipefitters, electricians, and maintenance technicians who need to cut, clean, or restore threads on fasteners and threaded openings across a range of common sizes. With 40 individual pieces, the set spans the most frequently encountered unified national coarse and fine thread sizes in light industrial and trade work.

This tap and die set is appropriate for shop use, field maintenance, and on-site repair tasks where threading or re-threading of bolts, rods, and threaded holes is required. Typical applications include restoring damaged threads on conduit fittings, equipment frames, and mechanical assemblies in HVAC, plumbing, and electrical installations. The range from 4-40 to 1/2-20 covers the fastener sizes most commonly encountered in residential and light commercial trade work.

Key Features

• 40-piece set covering 4-40 through 1/2-20 tap and die sizes
• Carbon steel construction for both taps and dies
• Bright finish on all taps for visual identification and corrosion resistance
• Hex die profile accepts standard wrenches for secure, controlled torque
• Non-adjustable hex dies provide consistent thread geometry
• Compact case dimensions for toolbox or service van storage

Compatibility

Designed for use with unified inch thread standards in the 4-40 through 1/2-20 range, suitable for general maintenance threading tasks across HVAC, electrical, and plumbing trade applications.

Installation Notes

Thread cutting and restoration should be performed by qualified tradespeople familiar with proper tapping procedures and appropriate cutting lubricants for the base material. Secure the workpiece firmly before tapping to prevent movement and tap breakage. Back the tap out periodically to clear chips and reduce binding. Replace worn or damaged taps and dies rather than forcing them, as broken taps in a workpiece are difficult to extract.