How to Install Helical Inserts
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About Helical Insert Length
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How to Install Key-Locking Inserts
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Black-Phosphate Steel Easy-to-Install Thread-Locking Inserts
A black-phosphate finish provides mild corrosion resistance. Also known as E-Z Lok, these inserts use Loctite® adhesive to keep them in place. The adhesive reaches full strength after 72 hours. Installation requires a drill bit and a standard tap. Then set the insert with a bolt and two nuts, or use an installation bit.
Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole.
To drive slotted inserts, you can use a slotted screwdriver instead of using an installation bit or a bolt and two nuts.
For technical drawings and 3-D models, click on a part number.
Stainless Steel Helical Inserts

Also known as Heli-Coil inserts, these inserts have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw. Installation requires a drill bit, a helical insert tap, an installation tool, and a prong break-off tool.
For technical drawings and 3-D models, click on a part number.
Inserts | Through-Hole Taps | Closed-End Hole Taps | Installation Tools | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Thread Size | Thread Pitch, mm | Thread Spacing | Installed Lg., mm | Drill Bit Size | For Max. Hole Dia. | Specifications Met | Pkg. Qty. | Pkg. | Each | Each | Each | ||||
18-8 Stainless Steel—Right-Hand Threaded | |||||||||||||||
M24 | 3 | Coarse | 36 | 31/32" | 31/32" | SAE MA3279-179 | 1 | 000000000 | 00000 | 000000000 | 0000000 | 000000000 | 0000000 | 000000000 | 000000 |
Stainless Steel Screw-Locking Helical Inserts

A distorted thread grips the screw to resist loosening. Also known as Heli-Coil inserts, these inserts have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw. Installation requires a drill bit, a helical insert tap, an installation tool, and a prong break-off tool.
Inserts that meet DIN 8140 adhere to international standards for dimensions.
For technical drawings and 3-D models, click on a part number.
Inserts | Through-Hole Taps | Closed-End Hole Taps | Installation Tools | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Thread Size | Thread Pitch, mm | Thread Spacing | Installed Lg., mm | Drill Bit Size | For Max. Hole Dia. | Specifications Met | Pkg. Qty. | Pkg. | Each | Each | Each | ||||
18-8 Stainless Steel | |||||||||||||||
M24 | 3 | Coarse | 36 | 31/32" | 31/32" | DIN 8140, SAE MA3329-179 | 1 | 000000000 | 00000 | 000000000 | 0000000 | 000000000 | 0000000 | 000000000 | 000000 |
Helical Inserts with Installation Tools

Inserts come with a through-hole tap and installation tool. Also known as Heli-Coil inserts, they have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw.
Thread Size | Thread Pitch, mm | Thread Spacing | Installed Lg., mm | Drill Bit Size | For Max. Hole Dia. | No. of Inserts Included | Includes | Each | |
18-8 Stainless Steel—Right-Hand Threaded | |||||||||
---|---|---|---|---|---|---|---|---|---|
M24 | 3 | Coarse | 36 | 31/32" | 31/32" | 5 | Through-Hole Tap, Installation Tool | 000000000 | 0000000 |
18-8 Stainless Steel Key-Locking Inserts

Made of stainless steel, these inserts have good corrosion resistance. Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. Use them to repair or change threads in soft metals such as aluminum. Inserts may be mildly magnetic. They’re comparable to Keensert® inserts. Installation requires a drill bit, a standard tap, an installation tool, and a hammer.
Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole.
For technical drawings and 3-D models, click on a part number.
Black-Phosphate Steel Key-Locking Inserts

A black-phosphate finish provides mild corrosion resistance. Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. Use them to repair or change threads in soft metals such as aluminum. They’re comparable to Keensert® inserts. Installation requires a drill bit, a standard tap, an installation tool, and a hammer.
Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole with stripped threads.
For technical drawings and 3-D models, click on a part number.
Inserts | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
For Tap | Each | Installation Tools | |||||||||||
Thread Size | Thread Pitch, mm | Thread Spacing | Thread Size | Thread Pitch, mm | Installed Lg. | Drill Bit Size | For Max. Hole Dia. | No. of Locking Keys | 1-9 | 10-Up | Each | ||
Black-Phosphate Steel with Thick Wall | |||||||||||||
M24 | 3 | Coarse | M33 | 2 | 33mm | 31 mm | 31mm | 4 | 000000000 | 000000 | 000000 | 000000000 | 000000 |
M24 | 2 | Fine | M33 | 2 | 33mm | 31 mm | 31mm | 4 | 000000000 | 00000 | 00000 | 000000000 | 00000 |
Key-Locking Inserts with Installation Tool

Drive the keys into the surrounding material for a more secure hold than thread-locking inserts. These inserts are used to repair or convert threads in soft metals such as aluminum. They’re comparable to Keensert® inserts.
Black-phosphate steel inserts are mildly corrosion resistant.
Choose inserts with a thick wall for greater strength than thin-wall inserts, or to fill a large hole.
For technical drawings and 3-D models, click on a part number.
For Tap | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Thread Size | Thread Pitch, mm | Thread Spacing | Thread Size | Thread Pitch, mm | Installed Lg. | Drill Bit Size | For Max. Hole Dia. | No. of Locking Keys | No. of Inserts Included | Each | |
Black-Phosphate Steel with Thick Wall | |||||||||||
M24 | 3 | Coarse | M33 | 2 | 33mm | 31 mm | 31mm | 4 | 2 | 000000000 | 0000000 |
Screw-Locking Key-Locking Inserts

Forming the strongest hold of any of our threaded inserts, these inserts have a distorted internal thread to lock screws into place and keys that drive into surrounding material to prevent slipping and rotating. This creates a mechanical lock, which is stronger than the chemical lock from adhesive on thread-locking inserts. Because they’re made of a solid piece of metal, these inserts are also stronger than helical inserts, which are made of coiled wire. They're often used in molds, tools and dies, and suspension systems in vehicles to create completely new threads, add strong threads in soft metal, or replace existing threads that are damaged or need to be resized.
A dry-film lubricant makes it easy to install them and screw fasteners in. To install, use a tap to create the threads in your material and an installation tool to drive the keys into the material. All are made to tight tolerances with strictly controlled materials. Many inch sizes also meet military or aerospace standards for dimensions and material.
These inserts resist corrosion in wet environments. Cadmium-plated steel inserts are stronger than 18-8 stainless steel inserts.
Inserts with thick walls are most commonly used; they’re stronger than thin-wall inserts and are used in larger holes.
For technical drawings and 3-D models, click on a part number.