HELI-COIL Helical Insert: Tanged Tang Style, Screw-Locking, 5/16"-18 Thread Size
The HELI-COIL Helical Insert is a tanged tang style, screw-locking insert in a plain finish, 100-pack. It features a 5/16"-18 coarse thread, right-hand direction, with an 18-8 material grade and tensile strength of…
SKU 3G-OTH-528905
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Product Description
The HELI-COIL Helical Insert is a tanged tang style, screw-locking insert in a plain finish, 100-pack. It features a 5/16"-18 coarse thread, right-hand direction, with an 18-8 material grade and tensile strength of 200,000 to 250,000 psi. Compatible with metal, this inch-system insert uses a 5/16"-18 STI tap size (MPN A3585-5CN312).
Frequently Asked Questions
What is a HELI-COIL helical insert used for?
A HELI-COIL helical insert repairs or reinforces tapped threads in metal. This screw-locking, tanged tang style prevents loosening under vibration. It is ideal for automotive, aerospace, and industrial maintenance applications where a strong, reliable 5/16"-18 coarse thread is needed.
What are the specifications of the HELI-COIL A3585-5CN312 insert?
This HELI-COIL insert has a 5/16"-18 coarse thread, right-hand direction, and an 18-8 material grade. It offers a tensile strength of 200,000 to 250,000 psi. The STI tap size is 5/16"-18, and it comes in a plain finish, 100-pack. It is compatible with metal substrates.
Where to buy HELI-COIL helical inserts worldwide?
3G Electric supplies HELI-COIL helical inserts worldwide. As a global industrial solutions provider, we handle full logistics and customs clearance to deliver the A3585-5CN312 screw-locking insert to your facility. Contact us for a quote and delivery timeline to your location.
How to install a HELI-COIL tanged helical insert?
To install a HELI-COIL tanged insert, drill out the damaged thread to the specified STI tap size (5/16"-18), tap the hole, then use a tang-style installation tool to wind the insert into place. After installation, break off the tang with a punch. Always follow the manufacturer's instructions for best results.
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3G Electric supplies HELI-COIL screw-locking tanged helical inserts. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.









