Section A: Introduction to HeliCoil Automated Installation Tools

HeliCoil automated tools are chosen for their convenience and speed of installation. They are extremely handy in times of production, when large volumes of inserts are involved. On average, using automated tools can reduce installation times by up to 80%*.

Automated tools significantly reduce fatigue on the user and increases output for the same given amount of time, thereby raising productivity.

There are broadly two types of automated tools, namely: electrical and pneumatic. In the next section, we will look at the electrical tool.

Helicoil Electrical Installation Tool	Helicoil Pneumatic Installation Tool

 

Section B: Introduction to HeliCoil Electrical Installation Tool

	Transformer The HeliCoil electrical tool is powered by a transformer that allows the power and speed to be adjusted.
	Electrical Driver The driver provides the body to hold the mandrel in place for installation.
	Electrical mandrel HeliCoil electrical mandrels operate in the same way as the manual ones, where inserts can be screwed onto the tip. The stopper is used simultaneously to set the length of the insert as well as to reverse the turning process automatically.

Section C: Installation Process with HeliCoil Electrical Tool

In this section, we will show the correct installation process for each type of installation tool. All the threaded holes shown have been tapped with a HeliCoil tap and are ready for insert installation.

	Setting the Mandrel By hand, screw the insert into the mandrel until the driving edge catches the tang.
	Determining the Length Leave a space of about 1 to 2 threads between the last thread and the stopper. This is to allow the insert to sit deep enough inside the threaded hole. This step is critical for work pieces with countersinking.
	Fixing the Stopper Using two small wrenches, jam the stopper against the hexagon nut, by turning the nut in an clockwise direction and the stopper, anti-clockwise.
	Fixing the Mandrel into the Driver Slot the mandrel into the driver, turn the adapter and let the keys grip the mandrel. Fasten more securely by using a chucky to lock the mandrel into place.
	Plugging In Make sure that the tool is correctly set up. There are two wires: a) The first wire connects the power socket to the transformer. b) The second wire connects the driver to the transformer.
	Loading the Insert – Part 1 Set the driver switch to “FOR” for clockwise movement, and depress the power button so that the mandrel is turning.
	Loading the Insert – Part 2 Place the insert at the tip of the mandrel, and position it such that the insert can be screwed in. The mandrel should catch and screw into the insert automatically. The insert is loaded.
	Installation Position the driver and mandrel on top of the threaded hole. Make sure that the tool is perpendicular to the work piece. Once ready, depress the power button and DO NOT release it. The insert will turn into the work piece and reverse automatically once the stopper touches the work piece.

 

Troubleshooting

In the course of using HeliCoil inserts, there are some important points we need to take note of to ensure smooth installation. Below, we list some common mistakes that occur and the steps to take in order to prevent them.

1. When tapping, the tap breaks.

Corrective action: Check that the hole is drilled to the correct diameter. Do not use drill bits that are worn as they may be undersized*. Also, always use tapping oil or lubricant when tapping.

*Just because a drill or tap is printed with a certain size, does not mean that the size will always be what is indicated (unless they are new). It is always critical to verify used drill bits and taps. For a rough reference, drill bits and taps will always wear considerably after usage for approximately 200 holes.

2. While installing, the insert is not able to enter the threaded hole.

Corrective action: Make sure that the hole is drilled and tapped to the correct diameter* and tolerance. Use a STI (screw thread insert) gauge if possible. When installing, make sure the insert is held in place by the collar and sits vertically on the hole before turning in. 

For screw-lock inserts, it is important to use prewinder-type tools, as the hexagon coil needs to be compressed before it can enter the tapped hole.

*Interchangeability is important. Make sure the brand of inserts used corresponds to the tap. Generic taps made by tap manufacturers who do not produce HeliCoil inserts may not match.

3. After installation, the coil does not sit properly on the tapped hole, and one (or more) of the threads “jumps”. As a result, the screw may not be fastened into the threaded hole.

Corrective action: Check that the hole is tapped properly, and that while installing, do not press down on the inserting tool. Use horizontal action to install the helical insert. For a more secure and smooth installation, use prewinder-type installation tools.

4. When breaking the tang off, it does not break fully, but is bent at an angle.

Corrective action: Check to make sure that the hole is deep enough for the tang to be completely broken off (there should enough space for the tang to bend 90⁰). 

5. After the tang is broken off, the screw cannot be fastened beyond the last thread. That is, when it reaches the bottom thread, it gets stuck.

Corrective action: Check that the last thread did not “jump”, as it could have been pulled downwards when the tang was broken off. Always use enough, but not too much force when breaking the tang off. Use an automatic spring-loaded tang break-off tool if possible.

 

Frequently Asked Questions (FAQ)

1. The insert, in its free state, does not fit ‘snuggly’ into the screw, but is bigger than the screw. Is this normal?

Answer: Yes, this is normal. The HeliCoil insert in its free state is always ‘oversized’, compared to the threaded hole. This is so that after installation, the insert is able to exert radial pressure and lodge itself against the work piece.

2. A certain thread insert has a nominal length of 10 mm as stated in the specifications table. However, when I measured the actual insert, it only shows 7 to 8 mm. At other times, it may even show only 5 to 6 mm. Is this correct?

Answer: Yes, this is normal. Due to wire tension, a thread insert may be more ‘compressed’ (where the coils stay close together) or ‘open’ (the coils stay further apart from each other). They should not be measured in their free state, and will reach their stated nominal lengths after they have been installed, as they will then follow the tapped thread dimensions. 

3. After the insert is installed, I checked the hole using a standard thread plug gauge. However, the No-Go side enters freely while sometimes, the Go side does not enter at all. Is this normal?

Answer: Yes, this is normal. Because the HeliCoil insert is made with a rhombus cross-section, this may differ from the angle of the standard gauge. Therefore, it is not necessary, and in fact, wrong to check the hole with a helical insert with a standard gauge. For checking, use a STI gauge before installing the threaded insert.

4. What length of insert should I use?

To determine which length to use, it is important to refer to the drilling and tapping depths chart (typically denoted by our symbols “Q”, “R”, “S” and “T”). They will tell you the effective thread engagement for every insert length.

5. What are Screw Lock inserts?

In addition to all the characteristics of the Free Running insert, Screw Lock inserts have one or more of its intermediate coils deformed polygonally. This serves to create strong resilient pressure onto the thread flanks of the bolt as it passes through.

6. What is the purpose of Screw Lock inserts?

The built-in Prevailing Torque of the grip coil positively locks the bolt, safeguarding against loosening under vibration or impact.

7. Why does my screw not enter freely into a hole that has a screw lock insert installed?

This is because our fingers do not provide sufficient force in fastening the screw. For correct installation, the initial threads can be fastened by hand. When the screw reaches the grip coil, you must use a driver (whether it be an Allen key or Philips screwdriver, depending on your screw) to fasten further.

8. Why are there so many types of HeliCoil inserts?

Technically, HeliCoil is a brand, so there is only one type of HeliCoil Insert. There are many types of screw thread inserts in the market, but they are known by different brand names.

9. Why is HeliCoil available from different manufacturers?

Originally, HeliCoil was invented and produced by Emhart Teknologies (known today as Stanley Engineered Fastening) from the USA in 1938. Till today, they are the only company in the USA to produce HeliCoil inserts.

Outside of USA, Bollhoff GmbH from Germany and Bollhoff Armstrong Ltd from the United Kingdom are the only companies licensed to produce HeliCoil inserts and tools.

10. Are all these HeliCoil inserts the same?

As long as an insert is produced from any of these companies, they conform to the same stringent and quality-assured standards. Unless special manufacturing instructions are given, their dimensions are all the same.

11. HeliCoil inserts produced from all 3 companies carry different part numbers. Why is this so? 

As every company has its own accounting system, their references to HeliCoil inserts and tools also change. However, official letters and Certificates of Conformity (COC) can be issued to verify the inter-changeability across all items.

12. Why are some stainless steel HeliCoil inserts darker in shade than others?

HeliCoil inserts are derived from stainless steel raw materials, which may be darker or lighter in shade. Depending on the origin of these raw materials, HeliCoil inserts may take the colour as well.

13. I noticed that some HeliCoil inserts are longer than others, even though they have the same nominal length. Correspondingly, the longer inserts have a wider gap between coils. Why is this so?

Being cold-rolled from stainless steel wires, HeliCoil inserts tend to have some spring-like properties, which may result in inserts being more “compressed” or “open”, thus appearing longer than others. This is not to be taken as the correct length of the insert, as the length is ultimately realized after the insert has been installed inside the threaded hole. A more accurate reading and verification of the length is to check the number of coils on the insert, which is given in our catalogue table.