Heli-coil A1185-04CN280 4-40 Unc Thread Insert 0.28 in

Product Description

The HELI-COIL A1185-04CN280 is a free running wire thread insert designed to create strong, durable internal threads in tapped holes. Built from 304 stainless steel with a bright, uncoated finish, this insert accepts 4-40 UNC fasteners and measures 0.28 inches in overall length, corresponding to a 2-1/2D length-to-diameter ratio. It features a tanged design for installation with a standard HELI-COIL installation tool. Electricians, machinists, and maintenance technicians install these inserts to repair stripped threads or to reinforce threads in soft or thin base materials.

This insert is suited for applications where a 4-40 UNC thread form is required and thread integrity or pullout resistance is a priority. Common use cases include thread repair in aluminum, magnesium, and other soft alloys, as well as original equipment assembly in electronics, aerospace components, and precision instruments. The 304 stainless steel construction resists corrosion in moderate environments. Each unit is sold individually, with a minimum order quantity of 10 pieces.

Key Features

• 4-40 UNC thread size for compatibility with standard 4-40 fasteners
• 0.28 inches overall length with a 2-1/2D length-to-diameter ratio
• 304 stainless steel construction for corrosion resistance
• Tanged design for use with standard HELI-COIL installation tooling
• Bright, uncoated finish - no coating interference with thread fit
• 8-7/8 free coils for full thread engagement across the insert length

Compatibility

Designed as an OEM-style free running thread insert for any application requiring a 4-40 UNC internal thread, including thread repair and original assembly in soft or damaged base materials.

Installation Notes

Installation requires a correctly sized HELI-COIL tap and a compatible installation tool for the 4-40 insert series - standard threading tools will not properly seat the insert. Power down or de-energize any equipment before performing thread repair on live assemblies. After installation, the drive tang should be broken off using a tang break-off tool; retain the tang and remove it from the work area to prevent contamination. Follow applicable equipment manufacturer specifications for hole preparation and insert seating depth.