Heli-coil A3585-04EN112 Screw-locking Insert 4-40 Unc

Product Description

The HELI-COIL A3585-04EN112 is a tangless screw-locking helical coil insert designed to create strong, vibration-resistant threaded holes in parent materials. Built from Grade 18-8 stainless steel, this insert accepts a 4-40 UNC screw thread and measures 0.112 inches in overall length, corresponding to a 1D length-to-diameter ratio. The tangless design eliminates the need for tang break-off after installation, reducing debris risk and simplifying installation in blind holes. Licensed mechanics, maintenance technicians, and assembly professionals use these inserts to repair stripped threads or build up thread strength in thin or soft base materials.

This insert is suited for light-duty fastening applications in precision assemblies, electronic enclosures, sheet metal components, and other structures requiring a reliable 4-40 UNC thread form. The 18-8 stainless steel construction resists corrosion, making it appropriate for environments with moisture exposure or mild chemical contact. With an outside diameter ranging from 0.144 to 0.159 inches, the insert installs into a properly prepared helical insert tap drill hole using a standard HELI-COIL installation tool sized for 4-40 thread.

Key Features

• Tangless design eliminates post-installation tang removal and reduces debris in blind holes
• Grade 18-8 stainless steel construction for corrosion resistance and durability
• 4-40 UNC thread size with 1D length-to-diameter ratio at 0.112 inches overall length
• Maximum locking torque of 48 oz-in with a minimum breakaway torque of 10 oz-in
• Outside diameter range of 0.144 to 0.159 inches for secure parent-material engagement
• 2-3/4 free coils provide consistent thread locking performance across the insert length

Compatibility

Designed as an OEM-style replacement or new-installation thread insert for applications requiring a 4-40 UNC screw-locking helical coil insert with a 1D length ratio.

Installation Notes

Installation requires a drill, a HELI-COIL tap sized for 4-40 UNC, and a compatible tangless installation tool. Power down or de-energize any assembly before drilling and tapping operations. Ensure the tap drill hole depth meets the insert length requirement before driving the insert. Do not over-drive the insert past the flush or slightly sub-flush seating depth specified for the application.