| Helicoils are an excellent solution when threads are stripped or damaged, and you need to restore the threads to their original condition. Helicoils are available in various sizes to accommodate different thread sizes, and they can be installed in a variety of materials, including metal, plastic, and wood. The installation process is relatively simple, but it does require some specialized tools and materials.
In this article, we will provide a step-by-step guide on how to install a Helicoil. We will cover everything from gathering the necessary tools and materials to testing the repaired threads. Whether you are a professional mechanic or a DIY enthusiast, this guide will help you install a Helicoil safely and effectively.
Before you begin the installation, it is important to gather all of the necessary tools and materials. You will need a drill, a tap, a Helicoil insert, a Helicoil installation tool, and a threadlocker.
Ensure you select the correct size drill bit for the Helicoil insert you are using, as this will ensure a precise fit. If you are unsure which size drill bit to use, consult the Helicoil manufacturer’s instructions. Once you have gathered all of the necessary tools and materials, you can begin the installation process.
The first step is to drill a hole in the damaged threads. The hole should be drilled to the depth specified by the Helicoil manufacturer. Once the hole is drilled, you will need to tap the hole to create threads for the Helicoil insert. After tapping the hole, you can insert the Helicoil insert into the hole. The Helicoil insert should be screwed into the hole until it is flush with the surface of the material. Once the Helicoil insert is installed, you can apply threadlocker to the threads to prevent the insert from coming loose. Finally, you can test the repaired threads, before putting the equipment back into service.
Tools and Materials Required for Helicoil Installation
1. Essential Tools
Helicoil Thread Repair Kit: The primary tool for Helicoil installation, this kit includes inserts, taps, and a helical wire insert tool. Choose the correct kit size and thread type based on the damaged thread.
Drill Bit: Select a drill bit slightly smaller than the inner diameter of the Helicoil insert. It should be the same size as the tap provided in the kit to ensure proper hole preparation.
Countersink or Chamfer Bit: This bit enlarges the top of the drilled hole, creating a recess for the Helicoil insert to sit flush with the surface.
Measuring Tools (Caliper or Vernier Calipers): Measure the outer diameter of the Helicoil insert and the depth of the drilled hole to ensure the insert is properly sized and installed.
Thread Lock: Apply a small amount of thread lock to the insert’s outer surface before installation to prevent it from loosening over time.
Tap Wrench or T-Handle: A lever to hold and rotate the tap when threading the insert into the prepared hole.
Extension Bar: Used to extend the reach of the tap when accessing deep holes.
Drill or Screwdriver: To power the drill bit and countersink or chamfer bit during hole preparation.
2. Additional Materials
- Cutting Fluid: Lubricates the drill bit and tap when drilling and threading.
- Cleaning Brush: To remove debris from the drilled hole and tapped threads before insert installation.
- Shop Rags: To wipe away any excess cutting fluid or debris during the process.
- Penetrating Oil: Optional, can be used to loosen the damaged thread if necessary.
Drilling the Damaged Hole
Before you can insert the Helicoil insert, you need to prepare the damaged hole by drilling it out to the correct size. This ensures that the insert has a secure and precise fit, allowing it to effectively restore the threads. Here’s a detailed guide to drilling the damaged hole:
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Select the Correct Drill Bit: Choose a drill bit that matches the recommended size for the Helicoil insert you’re using. Typically, the drill bit size is mentioned in the product specifications.
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Secure the Workpiece: Clamp or secure the workpiece firmly to prevent it from moving during drilling. This will ensure a straight and accurate hole.
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Mark the Center: Using a center punch or a scriber, mark the center of the damaged hole. This will serve as a guide for drilling.
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Start Drilling: Start drilling carefully, holding the drill bit perpendicular to the workpiece. Apply gradual pressure and avoid drilling too quickly to prevent damage.
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Drill to the Recommended Depth: Refer to the Helicoil product specifications for the recommended drilling depth. This depth is usually measured from the surface of the workpiece.
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Clear Debris: Stop drilling periodically to clean out any debris that accumulates. This will prevent the drill bit from clogging and ensures a clean hole.
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Check the Depth: Use a depth gauge or a caliper to verify that you have drilled to the desired depth.
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Deburr the Hole: Once the hole is drilled to the correct depth, use a deburring tool or a small file to remove any sharp edges around the hole. This will help ensure a smooth insertion of the Helicoil insert.
Tapping the Hole for the Helicoil Insert
Once you have selected the correct size and type of Helicoil insert, you need to tap the hole to accommodate it. This involves using a special tap tool that is designed to create threads that are slightly larger than the insert itself. The following steps provide detailed instructions on how to tap the hole:
- **Secure the workpiece:** Hold the workpiece securely in a vise or clamp to prevent it from moving while you are tapping.
- **Center the tap:** Position the tap tool in the center of the hole and ensure that it is perpendicular to the surface.
- **Apply cutting fluid:** Lubricate the tap with a tap fluid to reduce friction and prevent damage to the threads.
- **Turn the tap clockwise:** Slowly rotate the tap tool clockwise while applying gentle pressure. Do not over-tighten, as this can break the tap.
- **Remove the tap:** Once the tap has created enough threads, slowly turn it counterclockwise to remove it from the hole.
- **Inspect the threads:** Check the threads to ensure they are clean and free of debris. If necessary, use a tap brush or compressed air to remove any remaining material.
- Apply a generous amount of tapping fluid to the threads of the insert.
- Use a clean brush or cotton swab to evenly distribute the fluid over the entire surface of the insert.
- Ensure that all threads are properly coated, avoiding any dry spots.
- If necessary, use a syringe or dropper to inject tapping fluid into the insert’s internal threads.
- Let the tapping fluid sit on the insert for a few minutes to allow it to penetrate the threads thoroughly.
- Secure the tap in a vise: Place the tap with the tang facing up in a vise and tighten it securely.
- Score a line around the tang: Using a hacksaw or a utility knife, score a line around the tang, about 1/8″ from the base of the insert.
- Snap off the tang: Use pliers to grasp the tang and snap it off at the scored line. You may need to apply some force to break the tang.
- File off the sharp edges: Use a file or a Dremel tool to file off any sharp edges on the broken tang and smooth out the surface.
- Clean the hole: Use a brush or compressed air to remove any filings or debris from the hole.
- Lubricate the hole: Apply a small amount of oil or grease to the hole to lubricate the insert and prevent corrosion.
- Install the insert: Carefully screw the insert into the hole. The insert should be flush with the surface of the material.
- Position the pliers around the tang, close to the insert.
- Apply downward pressure and twist slightly to weaken the connection.
- Execute a quick, snapping motion to break off the tang.
- Use a bolt or screw with a similar diameter and thread pitch as the intended application.
- If the bolt or screw doesn’t engage smoothly, it may indicate an issue with the insert installation or thread alignment.
- Helicoil insert
- Drill bit
- Tap
- Installation tool
Cleaning and Lubricating the Hole and Insert
Proper preparation of the hole and insert is crucial for successful Helicoil installation. Follow these steps to ensure a clean and lubricated surface:
4. Insert Lubrication
Thoroughly lubricate the Helicoil insert before insertion. Use a high-quality tapping fluid specially designed for Helicoil installations. Here’s a detailed guide for insert lubrication:
Lubrication Table
| Benefit | Lubrication |
|---|---|
| Reduces friction | Prevents thread galling |
| Improves thread engagement | Ensures smooth insertion |
| Enhances insert’s durability | Reduces wear and tear |
Inserting the Helicoil Coil
The final step is to insert the Helicoil coil into the reamed hole. Here’s a more detailed guide with additional tips:
1. Lubricate the Helicoil Coil
Apply a thread-locking compound or lubricant to the Helicoil coil to reduce friction and facilitate smooth insertion.
2. Align the Coil with the Tap
Hold the Helicoil coil perpendicular to the workpiece and align it with the reamed hole. Guide the coil using the tap’s tang.
3. Start Threading the Coil
Turn the tap clockwise to thread the Helicoil coil into the hole. Apply gentle pressure and ensure the coil is threading evenly.
4. Monitor the Insertion Depth
As you insert the coil, use the depth gauge on the tap handle to monitor the depth. Stop threading when the coil is flush with the surface or at the desired depth.
5. Breaking the Tang and Removing the Tap
Once the coil is in place, align the tap’s tang with the break-off groove at the end of the coil. Tap the tang firmly with a hammer to break it off. Then, unscrew the tap to remove it from the coil.
| Tip | Description |
|---|---|
| Use a new tap for each Helicoil insertion | Dull taps can damage the coil and compromise its performance. |
| Clean the reamed hole before insertion | Debris can prevent proper threading and weaken the bond. |
| Apply even pressure during insertion | Uneven pressure can cause the coil to thread unevenly or damage the workpiece. |
Setting the Coil with the Installation Tool
1. Attach the Post to the Coil
Carefully align the tang of the post with the notch in the top of the coil’s first thread. Slide the post onto the coil until it fits securely.
2. Insert the Coil Into the Hole
Using the installation tool, insert the coil and post assembly into the hole. The coil’s edges should engage with the hole’s thread.
3. Rotate the Installation Tool
With the coil aligned properly, rotate the installation tool clockwise. Apply gradual and even pressure to avoid damaging the coil or the hole.
4. Engage the Tang
As you rotate, the tang will engage with the retaining groove inside the hole. This will secure the coil in place.
5. Remove the Installation Tool
Once the tang is fully engaged, hold the post firmly and carefully remove the installation tool by pulling it straight out.
6. Trim Excess Coil
The excess portion of the coil that protrudes above the surface of the hole needs to be trimmed to ensure a flush finish. Use a sharp hacksaw or coil removal tool to cut the excess portion cleanly and precisely.
a) Measuring Excess Length
Before trimming, measure the length of the excess coil by inserting a flat blade screwdriver into the hole. The depth at which the blade touches the top of the hole indicates the excess length.
b) Aligning Coil Removal Tool
Align the coil removal tool with the excess coil. Hold the tool perpendicular to the surface of the hole and use firm downward pressure.
c) Twisting and Trimming
Twist the coil removal tool clockwise while applying downward pressure. Rotate until the excess coil is trimmed to the desired length.
Breaking and Removing the Tool Tang
Once the insert has been wound into the hole, it’s time to remove the tang from the tap. Here are the steps involved in this process:
| Tool | Function |
|---|---|
| Vise | Holds the tap securely |
| Hacksaw/Utility knife | Scores the tang for breaking |
| Pliers | Snaps off the tang |
| File/Dremel | Smooths out the broken tang and sharp edges |
| Brush/Compressed air | Cleans the hole from filings |
| Oil/Grease | Lubricates the hole and insert |
Finishing the Installation
Now that the helicoil insert is properly installed, it’s time to finish the installation process:
8. Break Off the Tang
Using a pair of pliers, carefully break off the tang (the protruding part) of the insertion tool. Grip the tang close to the insert and snap it off with a quick, sharp motion.
Detailed Steps:
9. Verify Thread Engagement
Use a suitable bolt or screw to test the thread engagement of the helicoil insert. Screw the bolt or screw into the hole and verify that it engages smoothly and securely.
Tips:
10. Clean Up and Inspect
Remove any metal shavings or debris from the installation area. Inspect the helicoil insert and the surrounding area to ensure everything is properly installed and secured.
Table: Common Inspection Points
| Component | Inspection Points |
|---|---|
| Helicoil Insert | Securely installed, no visible damage or gaps |
| Hole | Clean, free of debris, no signs of thread damage |
| Surrounding Area | No metal shavings or other debris, no visible damage to the workpiece |
Testing the Repaired Hole with a Bolt
After installing the Helicoil insert, it’s crucial to verify its functionality by testing the repaired hole with a bolt.
Follow these steps to test the repaired hole:
9. Test the Repaired Hole
| Step | Description |
|---|---|
| 9.1 | Clean any remaining debris or cutting fluid from the hole using a compressed air gun or solvent. |
| 9.2 | Apply a thin layer of anti-seize thread lubricant to the threads of a new bolt that is the same size as the original bolt that was damaged. |
| 9.3 | Thread the lubricated bolt into the repaired hole by hand until it begins to tighten. |
| 9.4 | Use a torque wrench to tighten the bolt to the manufacturer’s recommended torque specifications. |
| 9.5 | Fully tighten the bolt using a torque wrench or the specified number of turns from the initial hand-tightening. |
| 9.6 | Remove the bolt and inspect the threads. They should be clean and free of any stripping or damage. |
| 9.7 | Re-install the bolt with an appropriate washer and tighten it to the required torque specifications. |
Benefits of Using a Helicoil
Helicoils offer numerous benefits, making them an ideal choice for repairing damaged threads:
1. Permanent Repair
Helicoils provide a permanent and reliable repair, unlike temporary solutions such as tap inserts.
2. Strong Thread Engagement
Helicoils create full-depth threads that engage with the mating fastener, ensuring a strong and secure connection.
3. Resistance to Loosening and Vibration
Helicoils prevent loosening and vibration-induced damage by tightly fitting within the repaired thread.
4. Extended Service Life
The increased thread strength and resistance to wear prolongs the service life of the repaired component.
5. Restoration of Original Thread Size
Helicoils can be sized to match the original thread, restoring the component’s functionality.
6. Simple and Quick Installation
Helicoils can be installed quickly and easily using specialized tools.
7. Cost-effective
Helicoils offer an economical solution compared to replacing damaged components.
8. Wide Range of Applications
Helicoils are suitable for use in a variety of materials, including aluminum, steel, and cast iron.
9. Resistance to Corrosion and Chemicals
Stainless steel Helicoils provide excellent resistance to corrosion and chemicals.
10. Thread Protection and Reinforcements
Helicoils can be used not only for repair but also for protecting and reinforcing threads in high-stress applications.
| Helicoil Benefit |
|---|
| Permanent repair |
| Strong thread engagement |
| Resistance to loosening and vibration |
| Extended service life |
| Restoration of original thread size |
| Simple and quick installation |
| Cost-effective |
| Wide range of applications |
| Resistance to corrosion and chemicals |
| Thread protection and reinforcement |
How To Install A Helicoil
A Helicoil insert is a threaded wire insert that is used to repair damaged or stripped threads in a metal component. It is a strong and permanent repair that can be used in a variety of applications.
To install a Helicoil insert, you will need the following tools:
The first step is to drill the damaged or stripped threads out of the metal component. The drill bit should be the same size as the insert you are using.
Once the threads have been drilled out, you will need to tap the hole to create new threads. The tap should be the same size as the insert you are using.
The next step is to insert the Helicoil insert into the hole. The insert should be screwed into the hole until it is flush with the surface of the metal component.
The final step is to use the installation tool to tighten the insert. The installation tool will apply a torque to the insert, which will cause it to expand and lock into the threads of the metal component.
