3591-10EN938 - INSERT, 5/8-18 UNF S/L

The Heli-Coil® 3591-10EN938 is a tanged, screw-locking wire thread insert precision-manufactured from Nitronic 60 stainless steel. Engineered to establish high-strength, anti-galling 5/8-18 UNF fine internal threads in low-density parent metals such as aluminum and magnesium, this insert features a tanged design for reliable driving and insertion depth control. Internal resilient locking coils exert constant radial pressure on the mating bolt to resist rotational loosening caused by severe shock and vibration, while the high-performance Nitronic 60 alloy composition provides exceptional galling resistance and wear protection without requiring secondary coatings or lubricants.

Tanged Wire Construction provides a sturdy driving notch for controlled installation and precise positioning within tapped holes.

Screw-Locking Mechanism features straight-segment internal coils that securely grip bolts to prevent vibration-induced loosening without needing external lock washers.

Nitronic 60 Stainless Steel offers superior resistance to galling, thread seizing, and wear under high-load and high-vibration conditions.

5/8-18 UNF Fine Threading reinforces soft parent metals and repairs damaged fine internal threads in heavy-duty structural components.

1.5D Nominal Length Ratio optimizes load distribution and thread engagement depth to maximize pull-out strength in critical joints.