Helical Thread Insert Kits

Why is the diameter of some helical thread inserts larger than the tapped hole?

Many helical thread inserts have a slightly larger diameter than the required hole diameter. When the helical insert is being installed, its diameter decreases due to applied torque on the insert's prong / tang. However, once the threaded insert gets installed, it operates like a spring to expand outward into the material and provide strong anchoring.

What is the difference between helical and key locking thread inserts?

• Helical inserts are free-running inserts that allow attachment with metal fasteners without using any coating or lubricant. They are ideal for particle-free environments and can expand after installation to secure themselves in the base material.
• Key locking inserts form the strongest hold of all threaded inserts on soft metal surfaces using their distorted internal threads / locking keys that prevent slipping or rotating by driving into the surrounding material. They have superior strength owing to their solid, one-piece metal construction, unlike helical inserts that are made of coiled wire.

How to install a helical thread insert?

• Select a drill bit according to the length of the insert / screw / bolt to drill out the damaged threading up to the required depth.
• Use an appropriately sized tap to re-thread the drilled hole in the material.
• Select a Helicoil thread insert and use the installation tool to wind the insert into the hole.
• Use the tang break-off rod or punch to remove the tang / prong and allow free passage of the fastener. Large-sized holes or spark plug inserts require long-nose pliers to bend the tang in & out alternately until the tang breaks free.
• The repaired threaded hole is now ready for fastening applications.

How to install a key-locking thread insert?

• Drill a hole according to the required application.
• Tap the drilled hole and wind the insert into the hole.
• Drive the key into the material using the installation tool & hammer.

Can thread inserts be removed once installed?

Yes, some thread inserts can be removed using removal tools that attach to them & unwind them in the direction opposite to that used during installation. Key locking or rock solid inserts can be removed by bending the locking keys out of the material and using a winding tool to remove the insert out of the base material.