Using a Helicoil Kit for Damaged Thread Repair

23 - Jan - 2025

Let’s face it, damaged threads can be a headache. Whether you’re working on your car’s spark plug hole, fixing a stripped thread in an automotive engine, or repairing threads in a metal component, a damaged thread can throw off your entire project. But don’t worry! We’re here to guide you through the process of repairing those pesky threads using a Helicoil kit, an excellent solution for restoring stripped or worn-out threads to their former glory.

What is a HeliCoil Repair Kit?

A Helicoil kit consists of a stainless steel insert, an installation tool, a drill, and other necessary components for thread repair. The primary purpose of a Helicoil is to restore the integrity of a damaged or worn-out threaded hole in metals or alloys. The stainless steel inserts are designed to provide a durable, wear-resistant surface for new threads, making hem perfect for high-stress applications such as automotive and aerospace industries.

If you’ve ever experienced stripped threads in a spark plug hole or in other machinery, you know how frustrating it can be. The Helicoil kit is your saving grace when it comes to getting things back in working order.

You can find a range of Helicoil kits that are tailored for specific applications, including standard thread repair, spark plug repair, and even for heavy-duty industrial purposes. For a closer look at our full range of Helicoil kits.

To learn more about why you should choose helicoils from other thread repair solutions, check out some of our blog articles here

Step-by-Step Guide: How to Use a Helicoil Repair Kit

Step 1: Assess the Damage

The first step before anything else is to assess the condition of the damaged threads. Ensure the hole is large enough to accommodate the Helicoil insert, and check for any additional damage that might interfere with the repair. If the hole is severely deformed or cracked, it may be necessary to replace the part entirely instead of attempting a thread repair.

Step 2: Gather Your Tools

A Helicoil repair kit usually comes with everything you need, including:

Helicoil inserts: These are the stainless steel coils that you’ll be installing.
Drill: To prepare the hole for the Helicoil insert.
Tap: To create new threads inside the hole.
Installation tool: This helps you screw the Helicoil insert into place.
Inserts in various sizes (depending on your needs).

You’ll also need some additional tools that aren’t typically included in the kit:

Protective gloves: To avoid sharp metal edges.
Safety goggles: To protect your eyes from debris while drilling.
Clamps: To secure the workpiece and ensure precision during the process.

Step 3: Prepare the Work Area

Before starting the repair, ensure your work area is clean and well-lit. It’s also important to wear the appropriate safety gear, such as protective gloves and safety goggles. Always ensure the workpiece is securely clamped to avoid any movement while you’re drilling and tapping.

Step 4: Drill the Damaged Hole

Next, you’ll need to use the drill included in your Helicoil kit to ream out the damaged threads. Make sure to use the right-sized drill bit for the Helicoil insert you’re using. Follow these tips:

Use steady, consistent pressure when drilling.
Drill straight into the hole to ensure you don’t create any misalignment.
Drill slowly to prevent overheating or damaging the material.

If you’re repairing a spark plug hole or a similar sensitive area, it’s essential to take your time and be extra cautious.

Step 5: Tap the Hole

Once the hole is drilled, it’s time to tap the hole using the provided tap. Tapping is crucial because it creates the threads that will hold the Helicoil insert in place. This step is the heart of the thread repair process, so it’s essential to get it right.

Make sure to tap the hole slowly and steadily, using cutting oil if necessary to reduce friction and prevent the tap from overheating. Always tap the hole straight—an angled hole could lead to a misaligned insert.

Step 6: Install the Helicoil Insert

Now comes the fun part! Using the installation tool, screw the Helicoil insert into the newly threaded hole. The insert should go in smoothly, and you’ll want to ensure it’s seated properly at the bottom of the hole.

One crucial step here is to break off the tang (the little tab at the end of the Helicoil insert). The installation tool is designed to allow you to do this easily. Make sure the tang is removed, as it could prevent the bolt from fitting correctly.

Step 7: Finish the Repair

Once the insert is installed, the repair is complete! Give the newly repaired threads a quick inspection to make sure everything looks right, and you’re good to go.

Safety Tips for Using a Helicoil Kit

We can’t stress enough how important it is to work safely when handling tools. Here are some additional safety tips:

Wear protective equipment: As mentioned before, don’t forget your gloves and goggles.
Secure the workpiece: Ensure the workpiece is tightly clamped to avoid slipping while drilling or tapping.
Stay organized: Keep your tools within reach and make sure everything is in its place to avoid accidents.
Use the right drill bit and tap size: A mismatch could lead to poor thread quality, which can make your repair fail.

For more safety guidelines, always check the instruction manual provided with your Helicoil kit.

Other Thread Repair Options

While Helicoil is a popular choice, it’s not the only option available. Let’s look at a few alternatives for thread repair:

1. Time-Sert Inserts

Time-Sert is another brand of threaded inserts that works similarly to Helicoil. The main difference is that Time-Sert inserts are designed for heavy-duty applications, and they provide a more robust, permanent solution. Time-Sert is often preferred in applications where high stress is involved, such as in automotive engines or aircraft parts. However, they tend to be slightly more expensive than Helicoil kits.

2. Thread Repair Compounds

If the damage isn’t too severe, thread repair compounds could be a quicker, less labour-intensive alternative. These compounds are typically applied directly to the damaged threads, filling in the gaps and hardening to form a new threaded surface. While these compounds can work well in certain situations, they’re not as durable or long-lasting as Helicoil inserts.

3. Helicoil vs. Time-Sert: Which is Better?

Both Helicoil and Time-Sert are great options, but they’re suited to different types of repairs:

Helicoil: Ideal for light-duty applications, more affordable, and easy to install.
Time-Sert: Better for heavy-duty applications, more durable, and can handle higher stress.

For more detailed comparisons, check out our product pages for Helicoil thread repair kits here.

Common Mistakes and Troubleshooting

Now, let’s address some of the common mistakes people make when using a Helicoil kit:

Drilling the hole incorrectly: If you don’t drill the hole to the correct size or at the proper angle, the insert won’t fit, and the repair will fail.
Tapping too quickly: Rushing the tapping process can cause the threads to be uneven, making it difficult for the insert to hold properly.
Inserting the Helicoil improperly: If the insert is not fully seated or if the tang is left attached, the repair could fail under stress.

In case of any issues, you can always re-drill the hole and reattempt the repair, making sure to follow the steps carefully.

Ready to tackle your thread repairs? Browse our full range of Helicoil kits and Helicoil inserts today and make sure you have everything you need for a job well done.