Heli-coil A3585-5CN469 5/16-18 Unc Locking Insert 304 Ss

Product Description

The HELI-COIL A3585-5CN469 is a screw-locking helical coil threaded insert designed to provide a hardened, wear-resistant internal thread in parent materials that require reliable locking performance. Manufactured from Grade 304 stainless steel with a bright finish, this insert accepts 5/16-18 UNC fasteners and measures 0.469 inches in overall length, corresponding to a 1-1/2D length-to-diameter ratio. The tangless design eliminates the need for tang break-off after installation, reducing installation time and preventing loose tang debris inside assemblies. It delivers a maximum locking torque of 60 inch-pounds and a minimum break-away torque of 7.5 inch-pounds. Maintenance technicians, machinists, and field service professionals across HVAC, plumbing, and mechanical trades install these inserts to restore or reinforce threaded holes.

This insert is suited for applications where vibration, repeated fastener cycling, or soft parent materials would otherwise cause thread stripping or loosening. Typical use cases include thread repair in aluminum housings, steel enclosures, and cast components across residential and light commercial mechanical systems. The 304 stainless steel construction resists corrosion in moist or chemically exposed environments. With 6-5/8 free coils and an outside diameter range of 0.380 to 0.400 inches, the insert provides consistent engagement and load distribution across the full thread length.

Key Features

• Tangless design eliminates post-installation tang removal and prevents debris contamination
• Maximum locking torque of 60 inch-pounds for secure fastener retention under vibration
• Minimum break-away torque of 7.5 inch-pounds ensures detectably positive locking action
• Grade 304 stainless steel construction resists corrosion and withstands repeated thermal cycling
• Bright finish with 6-5/8 free coils for consistent thread engagement across full insert length
• Outside diameter range of 0.380 to 0.400 inches for reliable interference fit in tapped parent holes

Compatibility

Designed as an OEM-style screw-locking insert for 5/16-18 UNC threaded holes requiring locking performance in parent materials across general mechanical and trade service applications.

Installation Notes

Installation is performed by machinists or qualified trade technicians using a HELI-COIL compatible installation tool matched to the 5/16-18 UNC thread size. The parent hole must be drilled and tapped to the correct HELI-COIL tap drill size before insert installation. Power down or de-energize any equipment being serviced before drilling or tapping operations begin. The tangless design requires a compatible tangless installation tool and does not require a tang break-off step after seating.