Heli-coil AT1185-04C224 4-40 Unc Tangless Insert 0.224 in

Product Description

The HELI-COIL AT1185-04C224 is a free running, tangless wire thread insert designed to restore or reinforce 4-40 UNC threads in metal, plastic, or composite base materials. Manufactured from 304 stainless steel with a bright, uncoated finish, this insert delivers corrosion resistance and consistent thread engagement in demanding service environments. The tangless design eliminates the need for tang break-off during installation, reducing debris and streamlining the process. At 0.224 inches overall length with a 2D length-to-diameter ratio, it suits applications where space and thread depth are constrained. Licensed technicians and precision assembly professionals install this type of insert to bring damaged or undersized threads back to full load-carrying specification.

This insert is suited for use in light-duty fastening applications across HVAC equipment, electrical enclosures, control panels, and general mechanical assemblies where 4-40 UNC thread repair or reinforcement is required. The free running configuration allows standard thread engagement without locking torque, making it appropriate for fasteners that require removal and reinstallation during routine service. Each unit is sold individually, with a minimum order quantity of 100 pieces, making this part practical for shops and technicians who perform recurring thread repair work.

Key Features

• Tangless design eliminates tang break-off step, reducing installation debris and time
• 304 stainless steel construction provides corrosion resistance in harsh or humid environments
• 4-40 UNC thread size with 0.224 inches overall length for compact thread repair applications
• Free running coil style allows normal thread engagement without added prevailing torque
• 6-3/4 free coils deliver consistent thread form and load distribution
• Bright, uncoated finish maintains dimensional accuracy without added coating thickness

Compatibility

Designed as an OEM-style thread repair insert for base materials tapped to accept 4-40 UNC wire thread inserts, including aluminum, steel, and plastic housings common in HVAC controls, electrical equipment, and precision mechanical assemblies.

Installation Notes

Thread insert installation requires a properly sized Heli-Coil tap and installation tool matched to the 4-40 insert series. Power down or de-energize any equipment before performing thread repair on electrical or control components. Follow the equipment manufacturer's service documentation and applicable codes such as NEC for electrical enclosures. Do not over-drive the insert beyond the specified seating depth, as this can distort the coil and compromise thread engagement.