Heli-coil A3585-04CNPF112 Screw-locking Insert 4-40 Unc

Product Description

The HELI-COIL A3585-04CNPF112 is a tangless, screw-locking wire thread insert designed to repair or reinforce threaded holes in softer parent materials. Manufactured from Grade 304 stainless steel with a primer-free finish, it installs into a 4-40 UNC tapped hole and provides a hardened, corrosion-resistant internal thread. The 1D length-to-diameter ratio keeps the insert compact at 0.112 inches overall length, making it well-suited for tight assemblies where axial space is limited. A locking feature built into the coil resists vibration-induced loosening without requiring adhesives or additional hardware. Licensed electricians, aerospace technicians, and precision mechanics are the typical installers.

This insert is used wherever a 4-40 UNC thread needs to be installed, restored, or strengthened in aluminum, magnesium, plastic, or other materials that cannot sustain full thread loads on their own. The tangless design eliminates the tang-removal step required by traditional insert styles, reducing installation time and removing the risk of a broken tang remaining in the hole. It is commonly found in electronic enclosures, control panels, HVAC equipment housings, and light-duty mechanical assemblies that see vibration or repeated fastener cycling.

Key Features

• Tangless design eliminates tang removal, simplifying installation and reducing debris risk
• Grade 304 stainless steel construction for corrosion resistance and thread durability
• Screw-locking coil geometry resists vibration loosening without adhesives
• Primer-free finish ready for immediate installation
• Maximum locking torque of 48 oz-in with a minimum breakaway torque of 10 oz-in
• Compact 1D length at 0.112 inches overall suits space-constrained assemblies

Compatibility

Designed as an OEM-style thread repair and reinforcement insert for 4-40 UNC threaded holes in parent materials requiring thread strength upgrades or stripped-thread restoration.

Installation Notes

Installation requires a properly sized HELI-COIL tap to prepare the parent hole before the insert is driven in with the appropriate tangless installation tool. Power down and de-energize any assembly before performing thread repair work on electrical or control components. Follow the fastener manufacturer's torque specifications for the mating screw after insert installation; do not exceed the insert's rated locking torque. Wear eye protection during installation to guard against metal chips from tapping operations.