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What is a Heli-Coil® & How Does a Heli-Coil® Work?

Last updated on September 7, 2023 2:30:00 PM

 

As the largest stocking Heli-Coil® distributor in North America and sole provider of oversize wire inserts and twinserts, Olander is the go-to online resource for threaded inserts, fasteners, and more. Within this all-inclusive Heli-Coil® guide, we will discuss what a Heli-Coil® is in addition to how they work, the types of Heli-Coil® inserts available on our site, how to use them, and the intricacies of the installation and removal process.

  1. What is a Heli-Coil®?
  2. How Does a Heli-Coil® Work
  3. Different Types of Heli-Coil®
  4. Heli-Coil® Installation and Extraction
  5. Wrapping Up

What is a Heli-Coil®?

A Heli-Coil®, is a threaded insert used to repair and reinforce threaded holes in robust materials like metals, plastics, and composites. You may have heard of these products referred to as wire thread inserts, which can also be used to describe a Heli-Coil®.

If you have a product or machine that you are struggling to get a screw or bolt into due to damaged or stripped threads, usually brought on through normal wear, corrosion, or over-tightening, this durable and reliable replacement part is just what you need.

Helicoils help ensure productivity and safety, and therefore they tend to be common in the automotive, aerospace, electronic, and manufacturing industries.

Read on to learn how helicoils work.

How Does a Heli-Coil® Work?

The external threads on a Heli-Coil® are intended to match a thread pattern within a hole so that the two can be intertwined together. The intention is that they are to create a brand-new thread that aligns perfectly with the original fastener you are needing to use.

As you are inserting a Heli-Coil®, it compresses and tightly grips to the sides of the hole, filling the space between the insert and the hole’s walls. You may be wondering, what stops it from rotating when I install my screw or bolt?

The Heli-Coil® is designed with a locking feature, typically found at the bottom, so when handled, the insert is locked in place and will not move. You now have strong, durable internal threads that you can use to place your screws, bolts, or fasteners into!

If you experience issues when trying to secure a screw or bolt into your product or machine, you should work to fix the issue right away using a Helicoil®. When you purchase a Heli-Coil® kit from Olander, we make it easier on you by providing every part needed to remove your old thread and accurately install a new one.

Continue on to better understand the different types of Heli-Coil® inserts that you can purchase here at Olander.

Different Types of Heli-Coil® Inserts

We offer multiple types of helicoils at Olander, including parts made of a variety of materials. The two primary types of Heli-Coil ® inserts we provide are free running inserts and self-locking inserts, which are available in standard tanged and tangless options.

Depending on the thread type you are looking to replace or reinstall, we also have helicoils made of stainless steel, titanium, and more.

Free Running Inserts

One type of Heli-Coil® that you can purchase at Olander is the free running insert. These inserts have circular, smooth coil threads that can be used from both ends. This common insert is great for wear resistance, thread abrasion, corrosion, and heat resistance.

The diameter of the thread is reduced in the beginning and expands with a spring-like action when anchored inside the hole. This screw thread insert is able to automatically expand or contract based on the size of the hole.

Self-Locking Inserts

Another type of Heli-Coil® found at Olander is the self-locking insert. These are designed to create load-bearing joints in metal materials. These inserts have one or more hex-shaped middle coils that can provide a self-locking torque to ensure that during installation, you do not need to take further action to lock the Heli-Coil® in place.

The threading grips the screw, preventing it from being able to loosen through vibration or impact. These products are colored with red printer’s ink dye for identification.

Tanged or Tangless

Understanding the distinction between tanged and tangless inserts could make a difference in the quality and safety of your end product. Each type of Heli-Coil® can be purchased in tanged or tangless to best meet your needs.

The main characteristic of a tanged insert is that the bottom piece of coil is bent at a 90-degree angle crossing the middle of the coil diameter. After your Heli-Coil® installation, that tang that is bent needs to then be removed in order to lock the Heli-Coil® in place.

On the other hand, tangless inserts have a drive notch in their first and last thread, making them bidirectional. The notch turns the insert, eliminating the need to remove any bent coil as you do with the tanged insert. These types of Heli-Coil® inserts are best when trying to eliminate any debris from getting in the coil.

Since there are no loose tangs left behind, there is less of a concern for future damage and costly repairs. Tangless inserts are known to protect tapped threads from stripping, corrosion, or wear. One of the best qualities is that they are easily adjusted and removable after installation if need be.

Heli-Coil® Materials

Once you determine which type of Heli-Coil® you need, you then must select which material is best for your application.

The first material option you can choose is made of 302 Stainless Steel. This standard, general-purpose material is ideal for original equipment installation and repair. It is slightly magnetic with a temperature range up to 800 degrees Fahrenheit. With it being a standard material, it comes in a wide variety of sizes.

You can also find helicoils made with Inconel X750, designed for products that are regularly exposed to high temperatures. This material is best used for gas turbine engines, nuclear applications, and well drilling. Although it is not magnetic, this high-strength thread can handle temperatures up to 1,000 degrees Fahrenheit.

Titanium is another great option, with a superior strength to weight ratio. Due to its material strength, it has high corrosion resistance and the highest tensile strength there is. It is non-magnetic as well, and handles temperatures up to 600 degrees Fahrenheit.

Finally, our Nitronic 60 products are ideal for vacuum environments. This material has wonderful gall resistance and is compatible with stainless steel screws. No additional coating or plating is required with this material, which can handle lower temperatures up to 500 degrees Fahrenheit. Nitronic 60 also allows for less friction and is non-magnetic.

Heli-Coil® Installation and Extraction

Now that you have chosen the Heli-Coil® you need for your project, it is time to learn how to install or extract a new thread.

Before you begin inserting a Heli-Coil® or removing one, make sure that you have a clean, safe environment to work in that is well-lit and organized. We recommend that you also wear appropriate safety gear to protect your eyes and hands when handling these Heli-Coil® tools.

In instances in which you are repairing an existing thread, use the specified drill bit size that was provided to you in the Heli-Coil® kit. You must first drill out the damaged or stripped hole with the correct size drill bit, leaving behind a hole that is slightly larger than the original threaded hole. It is important to use a drill press or handheld drill to create a straight and centered hole.

Once complete, you are ready for install.

How to Install a Heli-Coil®

Step 1: Tapping a Hole

When you are ready to create new threads inside your fresh larger hole, go ahead and grab the tap that is included in your kit. You first want to apply cutting oil or lubricant to the tap in order to reduce friction and help ease the process.

Now, turn the tap handle clockwise to thread it into the hole, making sure to always keep the tap perpendicular. This is to ensure that you are creating straight threads that are of even distance and the proper depth.

Step 2: Inserting a Heli-Coil®

Carefully grasp your Heli-Coil® insert and twist it onto whichever installation tool you have or is provided to you in the kit. You will then insert that tool, with the Heli-Coil® attached, into the newly tapped hole. This hand tool or power tool will help guide the Heli-Coil® into place. Gently turn the tool counterclockwise, at which time the part will grip the sides and anchor itself in place.

On the bottom of the Heli-Coil®, there is an insert that has a tang or key. That was used to help install the coil; however, it now needs to be removed to allow the insert to fully expand and set permanently in place. Lastly, ensure that the Heli-Coil® you installed is flush with the surface and properly anchored.

How to Remove a Heli-Coil®

If you are trying to remove a standard tanged Heli-Coil®, you will want to use the tang break-off tool that is typically found within a kit. Your goal is to snap off the tang so that you can better grab it and pull the Heli-Coil® out.

It is extremely important to twist the Heli-Coil® so that you are not damaging the newly established threads while doing this. Upon twisting the Heli-Coil®, it should pull up and out of the threads naturally with your assistance.

Wrapping Up

Here at Olander, we hope that you no longer have to ask yourself what a Heli-Coil®: is

Beyond that, we want you to have a deeper understanding about what helicoils are and how to use them to improve or repair your projects. As a leading supplier, you can find several types of Heli-Coil® inserts and all-inclusive kits to help you get the job done more efficiently.

Contact us today to find out more!

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