When internal threads wear out, strip, or need added reinforcement, two of the most common solutions are helicoils and threaded inserts. While the terms are sometimes used interchangeably, they are not the same thing. A helicoil is a type of helical wire insert designed to restore or strengthen threads inside a tapped hole, while threaded inserts more broadly include solid-bodied designs used to create durable internal threads in a range of materials.
What is a Helicoil (Helical)?
A helicoil is a threaded insert made from a helical coil of metal wire, typically formed from stainless steel or another durable alloy. Once installed into a prepared hole, it creates a new internal thread that matches the original fastener size. Because of its spring-like helical shape, the insert can fit tightly into the surrounding material while still providing a precise thread form on the inside.
What is a Threaded Insert?
A threaded insert is a metal or engineered insert that is installed into a part to create a usable internal thread for a screw or bolt. Unlike a helical wire insert, which is formed from coiled wire, a threaded insert is usually a solid piece with both internal and external features designed for retention. The outside of the insert may be threaded, knurled, barbed, or otherwise shaped so it stays anchored in the surrounding material after installation.
Browse Threaded InsertsKey Differences
| Difference | Helicoils | Threaded Inserts |
|---|---|---|
| Construction | Made from a helical coil of wire that forms internal threads once installed. | Solid-bodied insert with internal and external features. |
| Design Type | Wire-based thread reinforcement or repair solution. | Solid inserts in many styles and retention methods. |
| Typical Use | Restore damaged threads or reinforce threads in softer metals. | Create strong, durable threads in metals, plastics, wood, and composites. |
| Installation | Installed into a prepared and tapped hole, usually with a dedicated installation tool. | May be screwed in, pressed in, heat-set, molded in, or locked in depending on the insert type. |
| Strength | Improves thread wear resistance and load distribution, especially in lightweight materials. | Provides greater pull-out resistance and thread durability in demanding applications. |
| Space Requirements | Works well where wall thickness and installation space are limited. | Some designs require more surrounding material and installation depth. |
| Material Compatibility | Metal parts, especially aluminum and similar alloys. | Wide range of materials, including plastic, wood, and composite parts. |
| Repair vs. Original Design | Repair and metal thread reinforcement. | Both original product design and repair, depending on the application. |
| Reusability | Handles repeated fastener use better than bare parent material. | Selected where long-term thread life and repeated assembly are important. |
When To Use Each
Helicoils
- Best for repairing damaged threads in metal parts
- Commonly used in aluminum and other softer metals
- Helpful when the original fastener size needs to stay the same
- Good where space is limited around the hole
- Often chosen for thread reinforcement using a helical wire insert design
Threaded Inserts
- Best for creating stronger, more permanent internal threads
- Commonly used in plastic, wood, composites, and softer metals
- Better for applications with frequent assembly and disassembly
- Useful when higher pull-out resistance and long-term durability are needed
- Often preferred when the material does not hold threads well on its own
Parting Thoughts
MISUMI USA carries a wide range of Inserts, including – threaded inserts, tangless inserts, insert tools, helicals, and more. If you have any questions about fastening concerns for your next project or fix, please feel free to contact our product experts, and engineers. For more insights about thread inserts/helicals, and other manufacturing related articles be sure to check out our blog, and articles like – What Is a Helicoil and When Should You Use One?, 7 Tips for Using Helicals, 5 Facts About Helicals, and more.
Author: Scott Bredemann | Updated: 4/16/2026
Disclaimer:
The content on this webpage is for informational purposes only. MISUMI makes no guarantees, expressed or implied, regarding the accuracy, completeness, or validity of the information. Performance parameters, tolerances, designs, materials, or processes should not be assumed to reflect third-party suppliers’ or manufacturers’ deliverables within MISUMI’s network. Buyers are responsible for specifying their part requirements.