Thermal Spray And Tube Mills: A Closer Look at the Manufacturing Process

Thermal Spray And Tube Mills: A Closer Look at the Manufacturing Process

Bob McDemus here, and today I’ve got another video for you as we explore another way thermal spray is used in various industries.

Today we’re looking at tube mills and the automated process used to manufacture galvanized tubes.


First things first, let’s understand what a tube mill actually is. Tube mills are responsible for creating round and shaped tubes, like the ones you see in chain link fences or the tubes used in solar panels to track the sun. These tubes are made from flat sheets of galvanized steel, which go through a hot dip galvanizing process to coat them with zinc.

Now, let’s break down the manufacturing process step by step, as seen in the video. The process begins with a flat sheet of galvanized steel, which passes through a series of forming rolls that gradually curve it into a U-shape. These rolls continue to shape the sheet until it becomes a tube. It’s incredible to witness how a simple flat sheet can transform into a perfectly round tube!

One of the most fascinating parts of the process is the friction weld. Using an induction coil and a ballast, the two ends of the tube are heated to a glowing red temperature and then pressed together to create a seamless weld. No weld rod or additional material is required. It’s a testament to the precision and efficiency of modern manufacturing techniques.

After the weld, a scarfing tool is used to remove any excess material, ensuring a smooth and seamless finish. The tube then moves on to the automated thermal spray process, where molten zinc is sprayed onto the hot tube. This zinc adheres to the fresh weld area, providing a protective coating and restoring the galvanized properties of the tube.

Throughout the entire process, a coolant lubricant is used to cool down the tube and reduce friction. This lubricant also helps to prevent water from entering the weld area. The thermal spray process takes place in an enclosed box to contain the zinc dust, ensuring a clean and safe working environment.

Watching the video, it’s truly mesmerizing to see the precision and speed at which these tube mills operate. Some mills can reach speeds of up to 300 feet per minute, allowing for efficient production and meeting the demands of various industries. Tube mills are strategically located across the country to minimize transportation costs, as tubes are lightweight but take up a significant amount of space.

Based on the insights shared in the podcast episode, I have a couple of suggestions:

Embrace the versatility of automated thermal spray: Tube mills have a wide range of applications, from chain link fences to solar panels. As you see, an automated approach to thermal spray in this industry speeds up industrial manufacturing. 

Prioritize efficiency and production: Tube mills are designed to produce tubes quickly and efficiently. If you’re in the manufacturing industry, and not just in the tube mill industry, we can help optimize your processes to increase productivity and meet growing demands.
Manufacturing and incorporating automated thermal spray is what we’re passionate about and what we specialize in. The manufacturing process, as showcased in the podcast episode, highlights the precision, efficiency, and versatility of the manufacturing process. And that’s a wrap, folks!

If this topic intrigues you, there’s a wealth of further examples and applications to explore. The thermal spray process holds untold potential, making our lives better, safer, and more sustainable. If you have any questions or would like to learn more about how Thermal Spray Depot can help you, give us a call at 724-229-5791 or drop us a line at

Also, be sure to check out our Youtube channel for more videos about thermal spray.
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